As was said, the ammonium cation NH 4 plays the role of a metal cation and forms salts with acidic residues: NH 4 NO 3 - ammonium nitrate, or ammonium nitrate, (NH 4) 2 SO 4 - ammonium sulfate, etc.
All ammonium salts are crystalline solids, highly soluble in water. In a number of properties they are similar to alkali metal salts, and primarily to potassium salts, since the radii of the K + and NH + 4 ions are approximately equal.
Ammonium salts are obtained by reacting ammonia or its aqueous solution with acids.
They have all the properties of salts due to the presence of acidic residues. For example, ammonium chloride or sulfate reacts with silver nitrate or barium chloride, respectively, forming characteristic precipitates. Ammonium carbonate reacts with acids because the reaction produces carbon dioxide.
In addition, the ammonium ion causes another property common to all ammonium salts: its salts react with alkalis when heated to release ammonia (Fig. 133), for example:
or in ionic form:
Rice. 133.
Qualitative reaction to ammonium ion
This reaction is a qualitative reaction to ammonium salts, since the ammonia formed is easy to detect (in what ways can this be done?).
Laboratory experiment No. 31
Recognition of ammonium salts
The third group of properties of ammonium salts is their ability to decompose when heated, releasing ammonia gas, for example:
This reaction also produces gaseous hydrogen chloride, which evaporates along with ammonia, and upon cooling combines with it again, forming a salt, i.e., when heated in a test tube, dry ammonium chloride sublimes, but on the cold walls of the upper part of the test tube it again settles in in the form of white crystals of NH 4 Cl (Fig. 134).
Rice. 134.
Sublimation of ammonium chloride
The main applications of ammonium salts were shown earlier (see Fig. 132).
Here we draw your attention to the fact that almost all ammonium salts are used as nitrogen fertilizers. As you know, plants are able to absorb nitrogen only in bound form, that is, in the form of NH + 4 or NO - 3 ions. The remarkable Russian agrochemist D.N. Pryanishnikov found that if a plant has a choice, it prefers the ammonium cation to the nitrate anion, so the use of ammonium salts as nitrogen fertilizers is especially effective. A very valuable nitrogen fertilizer is ammonium nitrate NH 4 NO 3.
Let us note other areas of application of some ammonium salts.
Ammonium chloride NH 4 Cl is used for soldering, as it cleans the metal surface of the oxide film and solder adheres well to it.
Ammonium bicarbonate NH 4 HCO 3 and ammonium carbonate (NH 4) 2 CO 3 are used in the manufacture of confectionery products, since these compounds easily decompose when heated and form gases that loosen the dough and make it fluffy:
Ammonium nitrate NH 4 NO 3 mixed with aluminum and coal powders is used as an explosive - ammonal, which is widely used in mining.
New words and concepts
- Ammonium salts.
- Properties of ammonium salts due to ammonium ion, acidic residues. Decomposition of ammonium salts.
- Qualitative reaction to ammonium ion.
- Ammonium chloride, nitrate, carbonate and their applications.
Tasks for independent work
1) Cu + FeCl2= 2) Mg + FeCl2= 3) Zn + MgBr2= 4) Fe + KBr=
2. Does it react with a solution of phosphoric acid?
1) S 2) CaO 3) H2 4) NaCl
3.Sodium silicate solution reacts with?
1) iron oxide (2) 2) potassium nitrate 3) carbon monoxide (2) 4) hydrochloric acid
4. Are the following statements about safety rules for working in a chemical laboratory correct?
A) It is necessary to wear gloves when working with sodium chloride solution.
B) Oxygen in the laboratory is obtained in a fume hood.
5. Which of the following reactions is used to produce hydrogen in the laboratory?
1) decomposition of hydrogen chloride 2) decomposition of ammonia 3) interaction of potassium with water 4) interaction of zinc with dilute sulfuric acid
6. Copper (2) chloride is formed as a result of the interaction of cedia (2) oxide with:
1) hydrochloric acid 2) sodium chloride solution 3) ammonium chloride solution 4) chlorine
7. A solution of barium hydroxide reacts with each of two substances:
1) MgO and SO2 2) KCl(solution) and H2S 3) CO2 and H2O 4) FeCl3(solution) and HCl (solution)
8. Between what substances does a chemical reaction take place:
1) barium chloride and zinc sulfate 2) calcium carbonate and sodium nitrate 3) magnesium silicate and potassium phosphate 4) iron sulfate (2) and lead sulfide
9. Are the following judgments about the purpose of equipment in a chemical laboratory correct?
A. Crucible tongs are used to hold the test tube while heating.
B. Using a thermometer, measure the density of the solution.
1) only A is true 2) only B is true 3) both judgments are correct 4) both judgments are incorrect
10. The presence of hydrogen ions in a solution of hydrochloric acid can be proven by:
1) change in the color of phenolphthalein to crimson 2) change in the color of litmus to blue 3) release of hydrogen when adding zinc 4) release of oxygen when heated
11. Physical phenomena include:
1) souring of milk 2) sugaring of jam 3) burning of a candle 4) burning of food
12. The largest number of ammonium ions is formed upon complete dissociation of 1 mol:
1) ammonium sulfate 2) ammonium sulfide 3) ammonium nitrate 4) ammonium phosphate
13. Oxygen does NOT react with:
1) carbon monoxide (4) 2) hydrogen sulfide 3) phosphorus oxide (3) 4) ammonia
14. Each of two substances reacts with a solution of calcium hydroxide:
1) CO2 and CuCl2 2) CuO and HCl 3) HNO3 and NaCl 4) Al(OH)3 and KNO3
15. Carbon monoxide (4) interacts with:
1)KNO3 2)P2O5 3) Ca(OH)2 4)HCl
16.Are the following judgments about pure substances and mixtures true?
A. Mineral water is a pure substance
B. Perfume is a mixture of substances.
1) only A is true 2) only B is true 3) both judgments are correct 4) both judgments are incorrect
17. Both aluminum and sulfur oxide (4) react with:
1) hydrochloric acid 2) sodium hydroxide 3) oxygen 4) barium nitrate 5) carbon dioxide
_______________________________________________________________
1) a weak electrolyte is: a) sodium hydroxide b) hydrochloric acid c) distilled water d) sodium chloride solution 2) between what substancesIs it possible for an ion exchange reaction to release gas? a) H2SO4 and CA3 (PO4) 2 b) AL2 (SO4) and BACL2 B) Na2CO3 and HCL d) HNO3 and KOH 3) The sum of all coefficients in the ponon and reduced ionic equations of the reaction between copper chloride (2) and silver nitrate respectively EQUAL: a) 10 ; 3 b) 10; 6 c) 12 ; 3 d)12 ; 6 4) calcium carbonate can be obtained by an ion exchange reaction through the interaction of a) sodium carbonate and calcium hydroxide b) calcium sulfate with carbonic acid c) calcium chloride with carbon dioxide d) calcium with carbon monoxide (4)
write the equations for the reactions of a) nitrogen with lithium (indicate the oxidation states of the elements and indicate the oxidizing agent and reducing agent) b) producing ammonia fromammonium salts c) a solution of ammonium chloride with a solution of silver nitrate (in molecular and ionic forms)
PHOSPHORUS AND ITS COMPOUNDS 1. Write the reaction equations for the interaction of: a) phosphorus with oxygen b) phosphine (PH3) withhydrogen chloride
c) a solution of phosphoric acid with potassium hydroxide (in molecular and ionic forms)
2. How do you prove that red and white phosphorus are two allotropes of the same element?
3 . Three numbered test tubes contain solutions of phosphoric and hydrochloric acids and sodium phosphate. How can they be recognized experimentally? Write the corresponding reaction equations
4. Write the interaction reaction equations:
a) phosphorus with chlorine
b) phosphorus with magnesium
c) a solution of sodium phosphate with a solution of silver nitrate (in molecular and ionic forms)
5. Explain why phosphorus is distributed in nature only in the form of compounds, while nitrogen, which is in the same group with it, is mainly in free form?
6. Write the reaction equations that can be used to carry out the following transformations:
P->Ca3P2->(^H2O)PH3->P2O5
HELP WITH THE TEST! PLEASE! The reaction between ammonium chloride and calcium hydroxide occurs because: a) a precipitate forms b) ammonia gas is releasedc) salt is formed d) the reaction does not occur Ammonia burns in oxygen in the presence of a catalyst to form: a) nitrogen b) nitrogen oxide (||) c) nitrogen oxide (|||) d) nitric acid The degree of oxidation of nitrogen in the ammonia molecule: a)0 b)+3 c)-3 d)+5 Ammonia is...: a) a solution of ammonia in water b) a solution of ammonia in alcohol c) ammonium chloride d) table salt
Lab 1-2
Qualitative analysis of cations
Na+
Flame color reaction
Dip a clean hot wire into a solution of sodium chloride or put a little solid salt on it. Introduce the wire along with droplets or particles of sodium salt into the colorless flame of the burner - the flame will turn yellow.
K+
Flame color reaction
Volatile potassium compounds color the colorless flame with its characteristic purple. The violet color of the flame in the presence of sodium salts becomes invisible, since sodium compounds color the burner flame yellow.
Reactions with sodium hexanitrocobaltate (ΙΙΙ)
Place 1-2 drops of a solution of any potassium salt in a test tube, add 3-5 drops of sodium hexanitrocobaltate (ΙΙΙ) solution to it, add a few drops of 6 M acetic acid and rub with a glass rod on the walls of the test tube. In this case it will fall out yellow crystalline precipitate dipotassium sodium hexanitrocobaltate (ΙΙΙ) 
:
or in ionic form:
The reaction should be carried out in the presence of dilute acetic acid.
Reaction with sodium hydrogen tartrate
Place 2-3 drops of a solution of any potassium salt into a test tube, add 0.5 ml of sodium hydrogen tartrate solution and rub the glass rod against the walls of the test tube. After some time, a white crystalline precipitate will form:
or in ionic form:
Reaction conditions.
NH4+
Reaction with Nessler's reagent
Add to drop
dilute ammonium salt solution 1-2 drops of reagent solution. In the presence 
- ions form a characteristic red-brown precipitate; if traces are present, the solution turns yellow:
or in ionic form:
Other cations of the I analytical group do not interfere with the detection of ammonium ions by the Nessler reagent.
Reaction with alkalis
Place a few drops of ammonium salt solution in a test tube 
and add 5 drops of an aqueous solution of any of the strong bases - 
- and heat the contents of the test tube in the flame of a gas burner. Due to the decomposition of ammonium salt ammonia will be released:
or in ionic form:
Ammonia released can be detected in various ways:
by smell;
by the blueness of universal indicator paper moistened with distilled water and added to the vapor above the solution;
by the formation of ammonium chloride smoke when a glass rod moistened with a drop of concentrated hydrochloric (hydrochloric) acid is brought to the opening of the test tube.
Boiling with caustic alkalis or sodium or potassium carbonates
When exposed to caustic alkalis or sodium or potassium carbonates, as well as during prolonged heating, ammonium salts in solutions decompose with the release of ammonia gas.
Mg++
Action of strong bases.
When strong bases are added to solutions of magnesium salts, white precipitate
. When a weak base (ammonium hydroxide) is added, precipitation is incomplete, and in the presence of ammonium salts, no precipitate forms at all. Therefore, ammonium salts must first be removed from the solution.
Place a few drops of the solution in a test tube MgCl 2
, add a few drops of an aqueous solution of any of the strong bases -. Precipitation will form Mg(HE) 2
.
Into another test tube to the solution MgCl 2
instead of 
add ammonium hydroxide solution. Note which tube produces more sediment.
Reaction with sodium monohydrogen phosphate
Microcrystalloscopic reaction.
D 
For microcrystalscopic detection 
- ions in the form 
place a drop of solution 
on slide
. Then add a drop of solution from a capillary pipette to it first 
, then a drop of concentrated aqueous ammonia solution. Finally, add a crystal to the solution 
(sodium hydrogen phosphate). It is recommended to heat the slide. In the immediate vicinity of the sodium phosphate crystal, dendritic crystals appear; at a further distance, regularly formed crystals in the form of six-rayed stars appear. - magnesium ammonium phosphate 
or in ionic form
Examine the crystals under a microscope.
Ca++
Reaction with ammonium oxalate.
Place 1-2 drops of a solution of any calcium salt in a test tube, for example 
, and add 1-2 drops of acetic acid so that the reaction of the medium is acidic (in the case of the methyl red indicator, the color should turn orange). Add a few drops of ammonium oxalate solution 
In this case, it drops out immediately from a concentrated solution, and gradually drops out from a diluted solution. white fine crystalline precipitate
. In the presence 
Calcium oxalate is precipitated quantitatively:
or in ionic form:
Microcrystalloscopic reaction with sulfuric acid .
P 
place a drop of calcium chloride solution on a glass slide, then add a drop of diluted 
and lightly evaporate the mixture. In this case, beautiful characteristic tufts of needles –
gypsum crystals 
,
easily distinguishable under a microscope.
Flame color reaction
Calcium ions color the colorless flame brick red.
Ba++
Reaction with potassium chromate (or dichromate) .
Place 1-2 drops of a solution of some barium salt into a test tube, for example 
, and add a few drops of solution 
or . Heat the test tube on a burner flame. In this case it falls out yellow crystalline precipitate:
or in ionic form:
or in ionic form:
2
Drop reaction with sodium rhodizonate.
Place a drop of the neutral test solution and then a drop of an aqueous solution of sodium rhodizonate on the filter paper. Formed red-brown barium rhodizonate precipitate:
+
+
When cold in hydrochloric acid, barium rhodizonate turns into bright red barium hydrogenodizonate:
Flame color reaction.
The colorless flame is colored by barium ions yellow-green color.
Reaction with sulfuric acid or ammonium sulfate.
Place a few drops of water-soluble barium salt in a test tube, e.g.
barium chloride, add 1 ml of dilute sulfuric acid or ammonium sulfate solution. In this case it falls out white crystalline precipitate barium sulfate 
.
Al +++
Reaction with ammonium hydroxide.
Place 1 ml of aluminum salt solution in a test tube, e.g. 
, add a few drops of ammonium hydroxide solution to it and heat it. In this case it falls out white yellowefigurativesedimenthydroxidaaluminum:
or in ionic form:
Transfer the aluminum hydroxide precipitate along with the solution into a centrifuge tube and centrifuge. Drain the clear solution and divide the precipitate into two parts.
Carry out the following test reactions:
Therefore, it is a typical amphoteric compound.
Reaction with alizarin (1,2-dioxyanthraquinone)
Test tube reaction. Place 2 drops of a solution of any aluminum salt in a test tube and add 5 drops 
. In this case, a precipitate forms. Add a few drops of freshly prepared alizarin solution to the resulting precipitate and boil. Alizarin forms an intensely red compound with aluminum hydroxide called aluminum varnish. Aluminum varnish does not dissolve in dilute acetic acid. Therefore, after cooling the contents of the test tube, add a little acetic acid to a slightly acidic reaction (pH ~ 4-5). In the presence of aluminum ions, the red precipitate does not disappear.
Reaction conditions.
When carrying out a test tube reaction, the pH value at the beginning of precipitation should exceed 7, corresponding to a weak ammonia solution, and after precipitation, the pH may be less than 7, corresponding to a dilute acetic acid solution (pH = 4-5).
The reaction is carried out at boiling.
The presence of sediments of other hydroxides, even in small quantities, is undesirable, and in large quantities is unacceptable.
Cr+++
Oxidation C r +3 chromium in Cr +6
Place 2-3 drops of a solution of chromium (III) sulfate or nitrate in a test tube, add 5 drops of hydrogen peroxide to it 
, 3-5 drops of potassium hydroxide KOH. Heat the mixture to a boil.
In this case, oxidation of -ions occurs to 
-ions and coloring from blue-green goes into yellow.
Carry out the following test reactions with the resulting solution to confirm the formation of -ions.
Fe +++
Reaction with 
Place 1-2 drops of solution in a test tube or on a glass slide 
, acidify the solution with 1-2 drops of hydrochloric acid, add 2-3 drops of yellow blood salt - a solution of potassium hexacyanoferrate (II)
In this case it falls out dark blue precipitate of Prussian blue:
Reaction with ammonium thiocyanate.
Place 1 ml of solution in a test tube, dilute it with five drops of distilled water and add 3-5 drops of ammonium thiocyanate solution
. At the same time it appears blood red coloring:
or in ionic form:
Reaction with sodium, potassium or ammonium hydroxide.
When exposed to solutions 
And
on ions is formed brown-red sediment Fe(OH)3, soluble in acids:
Fe++
Reaction with 
Place 1-2 drops of solution in a test tube or on a glass slide FeSO 4 , add 2-3 drops red blood salt - solution of potassium hexacyanoferrate (III) In this case, formation is observed turnbull blue:
Zn++
Reaction with sodium, potassium and ammonium hydroxide.
When sodium or potassium hydroxide reacts with zinc chloride, it forms white precipitate Zn(OH) 2 , soluble in excess and .
Obtain a precipitate of zinc hydroxide in a test tube and separate it from the solution using a centrifuge. Divide the sediment into two parts. Dissolve one part of the precipitate in an acid solution, the other in a base solution. Write reaction equations confirming the amphoteric nature of zinc hydroxide.
Reactions of Mn++ ions
Reaction with sodium hydroxide and hydrogen peroxide.
Manganese ions are characterized by oxidation-reduction reactions.
One of the characteristic oxidation reactions 
in an alkaline environment is its interaction with. When exposed to hydrogen peroxide in an alkaline environment, colorless manganese (II) ions are oxidized into insoluble manganese (IV) compounds. 
or 
, painted brown:
or in ionic form
Perform oxidation of -ions to. To do this, place 1-3 drops of a solution of any manganese salt into a test tube and add a few drops of NaOH solution. A white precipitate of manganese hydroxide is formed, slowly turning brown due to oxidation in air:
Add a few drops to the resulting precipitate. The precipitate instantly becomes brown-black due to the rapid oxidation of manganese (II) ions.
Reaction conditions.
Oxidation
-ions up to
- -ions in an acidic environment.
Manganese (II) compounds are oxidized in an acidic environment by strong oxidizing agents into permanganic acid. One of the most important oxidation reactions in a nitric acid or sulfuric acid environment is the interaction of -ions with 
or 
. In this case, colorless compounds of divalent manganese () are oxidized to manganese compounds with an oxidation state of +7 ( 
), painted in violet-red color:
or in ionic form:
In the presence of reducing agents, including 
, oxidizing agents are reduced and . Therefore, solutions should not be acidified with hydrochloric acid.
Carry out the oxidation of -ions to -ions. To do this, place 1-2 drops of a solution of any manganese salt (nitrate or sulfate, but not chloride !), add 5 drops of diluted (1:1) nitric acid, add a small amount of oxidizing agent (lead dioxide) and heat the mixture to a boil. Pour 1-2 ml of distilled water into the test tube, without stirring, the contents of the test tube, and let the mixture stand for a while. A crimson-red color appears, caused by the resulting permanganic acid. Since it may contain manganese compounds as an impurity, it is recommended to perform a blank experiment, observing the same conditions, but without adding the test solution to the test tube. In the absence of impurities, color does not appear.
The described oxidation reaction to permanganic acid is a very sensitive reaction.
Reaction conditions
Qualitative analysis of anions
Cl-
Reaction with silver nitrate
To 1-2 ml of sodium or potassium chloride solution, add a few drops of nitric acid and solution 
. In the presence of Cl - ions, a white curdled precipitate of AgCl precipitates:
In the light the sediment darkens. To make sure that the resulting precipitate actually contains AgCl, since other ions also give similar precipitates, rinse the precipitate with distilled water and centrifuge. Drain the water. Add ammonia solution to the resulting precipitate. In this case, AgCl dissolves, forming a complex cation 
.
To the solution of the complex compound, add a solution of dilute 
. The complex ion is destroyed and AgCl precipitates again. The appearance of a precipitate serves as evidence of the presence of Cl - ions in the analyzed substance. The described reactions proceed according to the following equations:
Oxidation reaction
-ions to free chlorine
Place 5 drops of a solution containing -ions in a test tube, add 0.5 ml
concentrated solution 
, 5 drops concentrated and heat (under traction!). In this case, partial or complete discoloration of the solution and the release of chlorine gas are observed, which is opened using starch iodide paper (blue color).
The reaction proceeds according to the equation:
To detect the released C1 2, bring a wet
iodine starch paper. In the presence of chlorine, a blue color appears due to the release of elemental iodine:
Manganites, manganates, permanganates, manganese and lead dioxide, chromic anhydride, hypochlorous, hypochlorous and nitric acids, etc. have an oxidizing effect.
Reaction conditions.
or in ionic form:
Br-
Reaction with silver nitrate
Add a few drops of nitric acid and solution to 1-2 ml of sodium or potassium bromide solution. In the presence 
-ions, a yellowish cheesy precipitate forms AgBr. Check its solubility in sodium thiosulfate solution 
, in ammonia solution and in ammonium carbonate solution 
.
Oxidation reaction -ions chlorine water until free bromine
Place 5 drops of KBr solution in a test tube, 1-2 drops of diluted
0.5 ml of benzene and 2-3 drops of chlorine water. Shake the test tube. In the presence of -ions, benzene turns yellow-brown.
The reaction is applicable for the detection of -ions in the presence of - and 
-ions.
Reaction conditions.
J-
Reaction with silver nitrate.
Ions (unlike and -ions) with silver ions form a yellow cheesy precipitate, soluble only in solutions of potassium cyanide and.
Add a few drops of nitric acid and solution to 1-2 ml of sodium or potassium iodide solution. Check the solubility of the resulting precipitate in the solution.
Oxidation reaction - ions with chlorine water to free iodine
The reaction is carried out similarly to the oxidation of bromides with chlorine water. Place 5 drops of potassium iodide solution KJ, 1-2 drops of dilute sulfuric acid, 0.5 ml in a test tube
benzene and 1-2 drops of chlorine water. Shake the contents of the test tube. In the presence of -ions, the benzene layer turns red-violet:
With an excess of Cl 2, free iodine is not released and the benzene layer does not become colored:
All oxidizing agents used for the oxidation of HCl and HBr can also be used as oxidizing agents.
Reaction conditions.
Oxidation reaction -ions potassium permanganate
Place 3-5 drops of the test solution containing -ions in a test tube, acidify the solution with a few drops of diluted solution and add 1-2 drops of the solution to it.
In the presence of -ions, the solution becomes discolored in the cold and releases iodine. Moderate heating promotes the reaction:
Reaction conditions.
As soon as a red color appears, stop adding the solution and
excess is reduced with 1-2 drops of hydrogen peroxide. Excess hydrogen peroxide is decomposed by boiling the solution.
Iodate can be easily detected by adding potassium iodide to the resulting solution. In this case, iodine is released in greater quantities than during oxidation directly with permanganate:
N0 3 -
Reaction of nitrate reduction to ammonia with zinc or aluminum
Place 5 drops of a solution of potassium or sodium nitrate in a test tube, add 0.5 ml of NaOH or KOH solution to it and then add 25-50 mg of zinc dust or aluminum powder. To speed up the reaction, heat the mixture on a gas burner.
Zinc dust (or aluminum powder) in alkaline solutions reduces nitrates to ammonia:
The ammonia released during this process is detected as described previously.
Interaction with diphenylamine
Place 3 drops of diphenylamine solution on a glass slide 
in sulfuric acid and 2 drops of sodium nitrate solution. In the presence 
-ion appears dark blue coloring, caused by the oxidation products of diphenylamine with nitric acid.
SO 3 --
Sulfurous acid reduction reaction
Place 3-5 drops of a solution of sulfurous acid salt (for example, 
), 3-5 drops of freshly prepared concentrated hydrochloric solution 
and heat the contents of the test tube. Wherein
Place 1 drop of solution on a piece of filter paper 
and 1 drop of sodium rhodizonate or rhodizonic acid solution. This produces a red spot of barium rhodizonate. Moisten the red spot with 1-2 drops of sodium sulfate solution. In the presence of sulfates, the color of barium rhodizonate immediately disappears. Barium ions with sodium rhodizonate or rhodizonic acid give a red-brown precipitate that is not decomposed by dilute HC1. Barium rhodizonate is instantly discolored by sulfates and sulfuric acid due to the formation of insoluble barium sulfate. The reaction in question is specific and is used only for the detection of sulfates.
CO 3 --
R 
reaction of formation of carbon dioxide (carbon dioxide)
Place 1 ml of sodium carbonate solution Na 2 CO 3 in a test tube, add 2 M HC1 solution to it and quickly close the test tube with a stopper into which the outlet tube is inserted. Place the other end of this tube into a test tube with lime water (Fig.).
Carbon dioxide, passing through a solution of Ca(OH) 2, forms a white precipitate or cloudiness of CaCO 3.
Write the equation for the reaction in molecular and ionic forms.
RO 4 ---
Reaction with ammonium molybdate
Pour 1 ml of sodium phosphate solution into a test tube 
or potassium, add a few drops of 6M HNO 3 and a little solid salt - ammonium molybdate (NH 4) 2 MoO 4. Heat the contents of the test tube. A yellow precipitate of ammonium phosphomolybdate appears.
P.O. 4 3- + 3NH 4 + + 12 MoO 4 2- + 24 H + = (NH 4 ) 3 P.O. 4 ∙12 MoO 3 ∙2H 2 O↓ + 10 H 2 O
The precipitate easily dissolves in an aqueous ammonia solution.
Control task.
Salt given. Determine which cation and anion are included in its composition.
Salt analysis
1. Preliminary tests
a) Flame coloring.
Na+ - yellow
Ca 2+ - brick red
K+ - purple
Ba 2+ - yellow-green
Cu 2+ - green.
c) Checking the pH of aqueous solutions.
If pH > 7, then the salt contains a strong base cation (alkali or alkaline earth metal)
If pH = 7, then it is a salt formed by a strong base and a strong acid.
G) Effect of dilute sulfuric acid – only carbonate ions CO 3 2 – decompose by dilute acids releasing CO 2 .
e) Effect of concentrated sulfuric acid – decomposes Cl -, Br –, J -, NO 3 -, MnO 4 - releasing Cl 2, HCl, HBr, Br 2, J 2, NO 2, O 2, etc.
f) Detection of some cations.
N.H. 4 +
Add Nessler's reagent solution to a drop of sample. The appearance of a red-brown precipitate proves the presence of ammonium ion in the salt.
Add sodium hydroxide solution to the sample and heat. If there is an ammonium ion in the salt, the smell of ammonia appears, and a white coating of ammonium chloride appears on a stick moistened with a solution of concentrated hydrochloric acid.
Fe 3+
Add K4 solution to the sample. A Prussian blue precipitate forms.
Add a few drops of KSNS to the sample. A red color appears.
Fe 2+ Add K3 solution to the sample. The appearance of Turnbull's blue is noted.
2. Progress of analysis .
1. First, cations are determined in the sample.
2. At the second stage of analysis, anions are determined in the sample. Before this, preliminary tests are carried out for the content of Cl - and SO 4 -2 ions. To do this, solutions of AgNO 3 and Ba(NO 3) 2 are added to individual portions of the sample. The precipitation of a curdled sediment of AgCl and crystalline BaSO4 indicates the presence of these ions in the sample.
DocumentTest No. 1 Qualitative analysis. Heterogeneous equilibria SAMPLE SOLUTION Qualitative analysis Group and quality reactions to cations and anions necessary...
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Work program of the discipline “analytical chemistry” Profession: “Laboratory assistant-ecologist”
Working programmFor coloring complexes. 1h TOPIC: Qualitative analysis cations and anions 1. Interaction of barium ions... (1). Topic 6 Qualitative analysis cations and anions. Hydrogen sulfide classification cations. First analytical group cations (cations sodium groups...
How to eliminate the interfering influence of a large number of chloride ions when determining ammonium ion in water?
Silver nitrate?
Ammonium chloride Sodium chloride 0.9% Latin name Sodium chloride 0.9% Pharmacological groups Excipients, reagents and intermediates. ... Silver nitrate Silver nitrate - . Klerimed Klerimed.
What does TRILON have to do with chloride ions?
Ammonium salts can be detected using: sodium hydroxide, sulfuric acid, barium chloride, silver nitrate?
Barium chloride
Write molecular equations for reactions. 5. Which of the following substances will copper chloride II silver nitrate, sodium chloride, iron, phosphoric acid, potassium hydroxide react with?
Using sodium hydroxide, because ammonia is released - a gas with a pungent odor.
Ammonium sulfate and barium chloride, ammonium chloride and silver nitrate in molec and ionic forms need to be written please help
Nh4So3
bacl
agno3
Of all the oxidizing solutions considered, the solution of silver nitrate and copper nitrate turned out to be universal. ... Recipe 2 light brown color. - Sodium chloride 100 - Ammonium nitrate 100 - Copper nitrate 10.
Molecular total ionic abbreviated ionic equations for the reaction between barium nitrate and ammonium sulfate
Help me write the chemical name of THESE SALTS and what class they belong to
Unless I forgot chemistry (not sure about classes)
1- sodium bicarbonate (acid salt)
2- sodium carbonate (medium)
3- calcium carbonate (medium)
4- potassium carbonate (medium)
5- I don’t know what to call it, but the class is like double salts
6- mercuric chloride (medium)
7- no idea at all
8- ammonium nitrate,
9-silver nitrate
10 - I don’t know either
Using a titrated solution of silver nitrate, the titer of ammonium thiocyanate is determined in the following way. ... The principle of Mohr's method is based on the precipitation of chlorides with silver nitrate in the presence of potassium chromate K2Cl4.
5) Dolomite carbonate class (medium)
10) Potassium alum. I don't know the class.
What reagent is used to determine ammonium ion? Potassium sulfate, or silver nitrate, or potassium hydroxide, or barium chloride?
Silver nitrate.
As a result of the reaction, a dark precipitate of silver nitrate should form
What gases can be obtained by having at your disposal the following substances: sodium chloride, sulfuric acid, ammonium nitrate, water, ammonium nitrite, hydrochloric acid, potassium permanganate, sodium hydroxide, aluminum carbite...
Compose the equation for ion exchange reactions of ammonium chloride with silver nitrate and potassium hydroxide. Write the ionic equations.
So
NH4Cl + AgNO3 = NH4NO3 + AgCl
NH4+ + Cl- + Ag+ + NO3- = NH4+ + NO3- + AgCl
Cl- + Ag+ = AgCl
Since ammonium nitrate contains chloride ions, when interacting with the added solution of silver nitrate, a white precipitate will form, similar in appearance to a soap solution, that is, a precipitate of silver chloride will form.
How to get NH4NO3 from NH4Cl
Ammonium nitrate Iron nitrate Sodium nitrate Silver nitrate Sodium nitrite Hydrogen peroxide Calcium permanganate Mercury p.31. Aluminum hydroxide bromide sulfide chloride Ammonia gaseous liquid solution Ammonium nitrate oxalate...
How to prove using a reaction that ammonium chloride contains NH4+ and Cl- ions?
You can add water and you get hydrochloric acid and ammonia / there will be a pungent smell /.
Standardization of ammonium thiocyanate solution with silver nitrate. ... Chlorides, bromides, iodides are detected using a solution of silver nitrate as a reagent, and silver ion is detected by reaction with chlorides.
What mass of silver chloride will be obtained by reacting 10.7 g of ammonium chloride with silver nitrate?
AgNO3 + NH4Cl = AgCl + NH4NO3
53.5 ----143.5
10.7------x
x = 28.7 g
28.7: 143.5 = 0.2 mol
Standard solutions of silver nitrate, prepared from commercial preparations containing a certain amount of impurities, are established using chemically pure sodium chloride. ... 37. Determination of ammonium nitrogen in ammonium salts.
How to distinguish ammonium sulfate ammonium chloride ammonium nitrate
The last one smells =)))
Description. Barium chloride under standard conditions is colorless orthorhombic crystals. ... BO2 2 Barium Nitrate Ba NO3 2 Barium Nitride Ba3N2 Barium Nitrite Ba NO2 2 Barium Oxalate BaC2O4 Barium Oxide BaO Peroxide...
Unified State Examination in chemistry, trivial names of substances.
And to the question where??? look at the Chemical Encyclopedic Dictionary - everything is there
Ammonium chloride ammonium chloride, mouth. technical name - ammonia NH4Cl salt, white crystalline, slightly hygroscopic... This method consists of direct titration of chlorides and bromides with a solution of silver nitrate in the presence of...
Three numbered glasses without labels contain solutions of sodium chloride, ammonium chloride and ammonium nitrate...
Mix everything, mix thoroughly, add water. sodium chloride will dissolve, ammonium chloride will float, ammonium nitrate. will precipitate.
A solution of silver nitrate corresponds to 0.009 796 g of ammonium bromide. a solution of silver phosphate, which corresponds to no less than 99% ammonium bromide and no more than 1 p ammonium chloride.
Please take the chemistry test.
1) Magnesium dissolves easily in
3) HCl solution
2) It will interact with each of the substances: H2O, Fe2O3, NaOH
2) magnesium BUT IN GENERAL I WOULD SAY THAT THERE IS NO CORRECT VEHICLE HERE
3) With each of the substances whose formulas will interact: NaOH, Mg, CaO
4) copper(II) oxide
4) Iron(III) oxide does not interact with
2) water
5) Reacts with sodium hydroxide solution
1) P2O5
6) Determine the formula of the unknown substance in the reaction scheme: H2SO4 + .> MgSO4 + H2O 3) Mg(OH)2
7) Among the substances: CaCO3, Ba(NO3)2, CuSO4 - reacts with hydrochloric acid (s)
3) only CaCO3
8) It reacts with both calcium hydroxide and silver nitrate
2) ammonium chloride
What is ammonium nitrate, ammonium nitrate, ammonium nitrate. This is a fertilizer containing 34-35% nitrogen. ... ...pure nitric acid, 1 2 silver nitrate in crystals, and the objects must be covered with etching...
How to clean silver items?
It works well - with tooth powder!
Labels Silver nitrate for cauterization of blood vessels, silver nitrate salt, silver nitrate plus sodium chloride. ... CH3 2CHCH2CH2ONO2 Methyl nitrate CH3ONO2 Actinium III nitrate Ac NO3 3 Aluminum nitrate Al NO3 3 Ammonium nitrate...
Ili voskom.ili zubnoi pastoi
Ammonia
It depends on what. For blackening, you can use toothpaste.
Decorations - the cheapest toothpaste and brush
Brush with tooth powder or plain white toothpaste.
Translation into Russian ammonium chloride. agrovoc. ... iv salts, such as ammonium chloride, potassium chlorate, potassium carbonate, sodium carbonate, perborate, silver nitrate. ... The approach to ammonium nitrate is special due to the fact that...
Before you start cleaning your silver item, you must first wash it in warm, soapy water. Then coat with a mixture of ammonia and chalk. After the mixture has dried, the item must be rinsed very thoroughly with water and wiped with a dry cloth. Very oxidized silver is cleaned with a solution of 1/4 part sodium sulfate and 3/4 parts water. To ensure that silver spoons, forks and knives always shine, after use they should be immediately immersed in boiling water with a small amount of soda. Dark stains from egg yolks can be easily removed with ash. Spoons, knives, forks and other items made of cupronickel and silver can be cleaned with toothpaste and then wiped with a soft cloth.
"Take a bowl, line it with foil (so that not only the bottom, but also the walls are covered), put salt (1 tbsp in a small bowl), silverware and pour boiling water over it. Before your eyes, the silver will be cleaned. So that this happens evenly , you can stop him."
I checked it myself, it works great.
Chemistry assignment (Three test tubes without labels contain solids...)
1 Barium nitrate proves ammonium sulfate; the reaction results in precipitates of barium sulfate.
2 Silver nitrate prove ammonium chloride as a result of the reaction a precipitate of silver chloride is obtained.
Other ammonium salts that do not contain iron are prepared similarly to ammonium chloride, taking into account the solubility of this salt in water. ... Silver nitrate. Silver nitrate. GOST 1277-75.
Help
What is this...
Ammonium nitrate ammonium nitrate ammonium nitrate nitrate... Lapis pencil is sold in pharmacies, is a mixture of silver nitrate... 30%. Composition 3 Silver chloride I silver chloride silver chloride AgCl.
What is back titration
In direct titration methods, the analyte reacts directly with the titrant. To carry out analysis using this method, one working solution is sufficient.
Back titration methods (or, as they are also called, residue titration methods) use two titrated working solutions: a main and an auxiliary solution. For example, back titration of chloride ion in acidic solutions is widely known. First, a known excess of a titrated solution of silver nitrate (the main working solution) is added to the analyzed chloride solution. In this case, the formation reaction of slightly soluble silver chloride occurs: Ag+ + Cl- → AgCl. The excess amount of AgNO3 that has not reacted is titrated with a solution of ammonium thiocyanate (auxiliary working solution): Ag+ + SCN- → AgSCN. The chloride content can be calculated because the total amount of substance (mol) introduced into the solution and the amount of AgNO3 that did not react with the chloride are known.
Home Chemistry ammonium sulfate sodium hydroxide lead nitrate 2 iron chloride 3 sodium silicate hydrochloric acid silver nitrate chloride.
Bravo! As they say, there is nothing to add!
Help me solve two chemistry problems! please
What to ask your relatives for your 13th birthday?
Set - Young chemist "Large chemical laboratory.
This set includes all the experiments that are included in the small sets.
2490 rub.
Chemical elements and items included in the kit:
cobalt chloride
acetone
copper sulfate
sodium sulfate
potassium iodide
bromocresol purple
ferric chloride
methyl violet
potassium permanganate
10% hydrochloric acid solution
calcium hydroxide
phenolphthalein solution
10% nitric acid solution
zinc
sodium phosphate
calcium chloride
sodium hydroxide solution
10% aqueous ammonia solution
iron
copper
aluminum-oxalic acid
silver nitrate solution
nickel sulfate
hexane
ammonium dichromate
graphite rods
Light-emitting diode
electricity generator
Petri dish
test tubes
putty knife
dry fuel
test tube holder
evaporation cup
straw
slide
test tube with stopper with hole
L-shaped tube
filter paper
universal indicator paper
beaker
brush
nichrome wire
stand for test tubes
copper wire
4. What reagent is used to determine and by what criteria is the presence of ammonium cations in a mixture determined? ... 8. How can you distinguish the white precipitate of silver chloride from the white precipitate of mercury chloride I?
Ask for a Minecraft license or play games for five nights with Freddy.
Lord, what are you asking???
Here is the list of a 13-year-old boy:
From mom - tablet
From dad - Moped
From Aunt, Uncle - video console
From Grandma, Grandpa - New gaming computer
You're great, develop your talent). Think carefully, search the Internet. I was interested in history, and always asked me to buy textbooks for the 10th grade.
In this case, I advise you to ask for the 4M scientific and educational set “Amazing Crystals”: http://www.mishamasha.ru/catalog/igrushki_i_knigi/poznavatelnye_i_obuchayushchie_igrushki/nauchno_poznavatelnyy_nabor_4m_udivitelnye_kristally_bolshoy_nabor.html
help me please
I don't understand hee hee
Ammonium chloride, sulfate, ammonium carbonate, silver nitrate, barium chloride, sodium hydroxide, sulfuric acid, litmus. paper, chemical glassware for conducting experiments. March 21, 2012
>> Chemistry: Ammonium salts
As was said, the ammonium cation NH4+ plays the role of a metal cation and it forms salts with acidic residues: NH4NO3 - ammonium nitrate, or ammonium nitrate, (NH4)2SO4 - ammonium sulfate, etc.
All ammonium salts are crystalline solids, highly soluble in water. In a number of properties they are similar to alkali metal salts, and primarily to potassium salts, since the radii of the K+ and NH+ ions are approximately equal.
Ammonium salts are obtained by reacting ammonia or its aqueous solution with acids.
They have all the properties of salts due to the presence of acidic residues. For example, ammonium chloride or sulfate reacts with silver nitrate or barium chloride, respectively, forming characteristic precipitates. Ammonium carbonate reacts with acids because the reaction produces carbon dioxide.
In addition, the ammonium ion provides another property common to all ammonium salts: its salts react with alkalis when heated to release ammonia.
This reaction is a qualitative reaction to ammonium salts, since the ammonia formed is easily detected (how exactly?).
The third group of properties of ammonium salts is their ability to decompose when heated, releasing ammonia gas, for example:
NH4Сl = NH3 + HCl
This reaction also produces gaseous hydrogen chloride, which evaporates along with ammonia, and upon cooling combines with it again, forming a salt, i.e., when heated in a test tube, dry ammonium chloride sublimes, but white crystals appear on the upper cold walls of the test tube again NН4Сl (Fig. 32).
The main areas of application of ammonium salts were shown earlier, in Figure 31. Here we draw your attention to the fact that almost all ammonium salts are used as nitrogen fertilizers. As you know, plants are able to absorb nitrogen only in bound form, that is, in the form of NH4 or N03 ions. The remarkable Russian agrochemist D.N. Pryanishnikov found that if a plant has a choice, it prefers the ammonium cation to the nitrate anion, so the use of ammonium salts as nitrogen fertilizers is especially effective. A very valuable nitrogen fertilizer is ammonium nitrate NH4NO3.
Let us note other areas of application of some ammonium salts.
Ammonium chloride NH4Cl is used for soldering, as it cleans the metal surface of the oxide film and solder adheres well to it.
Ammonium bicarbonate NH4NC03 and ammonium carbonate (NH4)2CO3 are used in confectionery, as they easily decompose when heated and form gases that loosen the dough and make it fluffy, for example:
NH4HC03 = NH3 + H20 + CO2
Ammonium nitrate NН4NO3 mixed with aluminum and coal powders is used as an explosive - ammonal, which is widely used in mining.
1. Ammonium salts.
2. Properties of ammonium salts due to ammonium ion, acidic residues. Decomposition of ammonium salts.
3. Qualitative reaction to ammonium ion.
4. Ammonium chloride, nitrate, carbonate and their applications.
Write the reaction equations (in molecular and ionic forms) between the following pairs of substances: a) ammonium sulfate and barium chloride; b) ammonium chloride and silver nitrate.
Write reaction equations characterizing the properties of ammonium carbonate: interaction with acid, alkali, salt and decomposition reaction. Write the first three equations also in ionic form.
With polybasic acids, ammonia forms not only intermediate, but also acidic salts. Write the formulas of the acid salts that it can give when reacting with phosphoric acid. Name them and write the dissociation equations for these salts.
Draw up molecular and, where possible, ionic reaction equations that can be used to carry out the following transitions:
N2 -> NH3 -> (NH4)2 HPO4 -> NH4Cl -> NH4NO3
Determine the amount of substance, volume and mass of ammonia required to produce 250 kg of ammonium sulfate used as fertilizer.
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