Hydrochloric Acid [ HCl]
1
2
3
4
5
6
7
8
9
10
11
Type of questions
Fill in the blanks
Explain why/ Give Reason
Give reason/Explain why?
Distinguish between
Define
Reactions /Balanced equations
What do you observe
Direct question
Identify
Miscellenious
HOTs
Fill in the Blanks
Q.
Fill in the blanks
The statements given below pertain to HCl gas or HCl acid. Complete the statements with
appropriate words. [1 mark of each blank space]
 Hydrogen chloride gas is not dried by using __________ [conc H2SO4/P2O5].
 Addition of __________ [sodium nitrate/zinc nitrate/silver nitrate] to hydrochloric acid,
gives an insoluble ppt. of the respective chloride. This ppt. is __________
[soluble/insoluble] in ammonium hydroxide and __________ [soluble/insoluble] in
dilute nitric acid.
 Hydrogen chloride gas on heating above 500°C gives hydrogen and chlorine gas. This
reaction is an example of __________ [thermal decomposition/thermal dissociation].
 Addition of __________ [iron (III) sulphide/iron (II) sulphide/iron pyrities] to dilute
hydrochloric acid results in the liberation of hydrogen sulphide gas.

Iron reacts with hydrogen chloride gas forming __________ [iron (II) chloride/iron (III)
chloride] and hydrogen gas. The reaction is an example of ________ [double
decomposition /synthesis/ simple displacement].
 Hydrochloric acid can be converted into chlorine by heating it with __________
[calcium oxide/lead (II) oxide], which acts as a/an __________ [oxidising/reducing]
agent.
 Hydrogen chloride and water are examples of __________ [polar covalent/non polar
covalent] compounds and the solution of hydrogen chloride in water __________
[contains/does not contain] free ions.
 An aqueous solution of HCl gas is named __________ [aquafortis/oil of vitriol/muriatic
acid].
 The salt obtained when rock salt reacts with conc. sulphuric acid below 200°C is a/an
__________ [acid/normal] salt.
 In the preparation of HCl acid from HCl gas, a funnel arrangement provides __________
[more/less] surface area for the absorption of gas.
Q.
Select the correct words from the list given below to complete the following word
equations : metallic oxide, active metal, metal carbonate, metal bisulphite, metal
hydroxide, metal bicarbonate, metal sulphate and metal sulphide.
 __________ + HCl (dil.)  Metal salt + water + Carbon dioxide gas
 __________ + HCl (dil.) Metal salt + hydrogen sluphide gas
 __________ + HCl (dil.) Metal salt + hydrogen gas
 __________ + HCl (dil.) Metal salt + water + sulphur dioxide gas
 _______ + HCl (dil.)  Metal salt + water
Q.
Complete the following statement using correct word from the
[5]
bracket given below
[ SO2, Hydrogen, more, less, 3:1, aqua regia, Cl2, 1:3, higher, lower, sulphur, muriatic acid,
Aquafortis, boiling, melting, saturated, quicklime, H2SO4 ]
The aqueous solution of HCl gas is named as (A)_____________.The ions which imparts acidic
properties to the aqueous solution of hydrogen chloride is (B)______________.The funnel
arrangement in the preparation of hydrochloric acid from hydrogen chloride provides
(C)_____________ surface area for the absorption of the gas. The proportion of hydrochloric acid and
nitric acid in Aqua regia is (D)_________________.Hydrochloric acid cannot be concentrated beyond
certain limit as it forms constant (E)____________mixture. Hydrogen chloride gas fumes in moist air
due to its (F)___________ solubility in water .Hydrogen chloride gas is not dried
using(G)________________.Hydrochloric acid on reaction with sodium thiosulphate librates(H)
______________ and ( G)______________.
One word/ Name the following
Q.
Name the following
 A black substance which on treatment with HCl liberates greenish yellow gas.
 Name a gas other than Hydrogen chloride which gives white fumes with ammonia.
 The product formed when conc nitric acid is reacted with conc. hydrochloric acid in 1:3
ratio
 Name the substance which will oxidise conc. hydrochloric acid to chlorine
 Soluble complex of silver salt with NH4OH.
 Mixture of one part of Conc. HNO3 and three parts of conc. HCl
 An experiment to prove high solubility of ammonia.
 A white compound which is insoluble in Nitric acid but soluble in Ammonium hydroxide
 Name the lead compound that can be used to oxidize hydrogen chloride to chlorine.
 Select the correct compound from the list – Ammonia, Copper oxide, Copper sulphate,
Hydrogen chloride, Hydrogen sulphide, Lead bromide – which matches with the
description given below : This compound can be oxidized to chlorine.
Q
Q
Name two gases which react chemically to form a solid.
Name a metallic chloride which is soluble in excess of ammonium hydroxide.
Q
Select the correct word/formula from the choices given below :
(i) A substance which reacts with conc. HCl to liberate chlorine. [PbO/PbO2/PbCl2]
(ii) An acid which is not monobasic acid [HNO3/HCl/HCOOH/H2SO4]
(iii) A metal which reacts with dil HCl to liberate hydrogen [Zn/Cu/Ag/Pb]
(iv) An acid which is not an oxidising agent. [H2SO4/HNO3/HCl]
(v) A salt insoluble in cold water, but soluble in hot water. [(PbCl2/PbSO4/PbS]
1.
Q
What must be added to the sodium chloride to obtained hydrogen chloride
Explain why / Give reason
Q
Exlain why? /Give reason











When the stopper of a bottle full of Hydrogen Chloride gas is opened there are fumes in
air?
Calcium oxide is a very good drying agent but it is not use to dry Hydrogen chloride gas.
Hydrogen chloride gas is soluble in water but not in toluene. Comment.
Why does hydrochloric acid attack and chemically burn our skin?
Why is the gastric juice of mammals acidic?
Why HCl is considered polar covalent compound?
Why is hydrogen chloride not collected over water.
Why is the gastric juice of mammals acidic? [1]
Why HCl is considered polar covalent compound? [1]
Why are conventional drying agent such as calcium oxide and phosphorus pentoxide not
used for drying moist HCl gas? Give equations
Why dilute hydrochloric acid cannot be concentrated beyond certain concentration on
boiling. [2]
Q
In the laboratory preparation of HCl gas from sodium chloride, state, why the following are
preferred.
(i) Conc. H2SO4 as reactant
(ii) Temp. of reaction mixture below 200°.
(iii) Conc. H2SO4 as drying agent.
Q
State which of the two — a solution of HCl in water and a solution
electrolyte. Give reasons for your answer. [2]
Q
State, why HCl gas fumes in moist air. [1]
Q
State your observation when a rod dipped in ammonium hydroxide solution is taken in the jar of
HCl. Support your answer by a chemical equation. [2]
Q
How come hydrochloric acid should be added to water rather than the reverse?
of HCl in toluene is an
Q
Q
By giving a reason explain why dilute HCl connot be concentrated by simple distillation. [1]
Explain, why silver nitrate crystals are dissolved in distilled water and not in tap water in order to
prepare a solution of silver nitrate as a laboratory reagent. [4]
Distinguish between
Q.
Distinguish between the following Manganese [IV] oxide and Copper oxide
 Ammonium chloride and Sodium chloride
Q
How can you distinguish between HCl gas and carbon dioxide gas by one test ?
Define
Q
Explain the term constant boiling mixture. [2]
Reactions / Balanced equations
Q. Refer the following flow chart given below and give balanced equation for the following conversions
A to D
Iron [II] Chloride
Sodium
Hydrogen
Chloride
Chloride
Q.
Write and balance the following reactions





Ammonium Chloride
Lead Chloride
Red lead + Conc. Hydrochloric acid 
Sodium thiosulphate + Dil. Hydrochloric acid
Bleaching powder + Dil. Hydrochloric acid
Red lead + Conc. Hydrochloric acid
Sodium thiosulphate + Dil. Hydrochloric acid
Write the equation for the reaction of hydrochloric acid with lead nitrate solution.

Write balanced chemical equation for the reaction of dilute hydrochloric acid with (a)
copper oxide (b) zinc (c) calcium bicarbonate.
Write the equation for the reaction of hydrogen chloride with ammonia.

Q
Write the equation for the following reaction :
i.
ii.
Dil. HCl and sodium thiosulphate.
Dil. HCl and lead nitrate solution.
Q
What must be added to sodium chloride to obtain hydrogen chloride. Write the equation for
the reaction.
Q
Write the equation for the preparation of hydrogen chloride from sodium chloride and sulphuric
acid. State whether the sulphuric acid should be concentrated or dilute.
Give an equation for preparation of HCl gas by synthesis.
Q
Q
State the products formed and write chemical equations when the following substances are
treated with hydrochloric acid.
(a) Calcium carbonate
(b) Magnesium hydrogen carbonate
(c) Ferric hydroxide
(d) Copper oxide
(e) Sodium nitrite
(f) Zinc sulphide
(g) Aluminium metal
(h) Potassium sulphite
(i) Potassium nitrate
[2 each]
Q
Q
Q
Write equation for the reaction which takes place in above [1]
What would you see when hydrogen chloride mixes with ammonia
Write the equation for the reaction of hydrochloric acid with each of the following;
1. Sodium sulphite 2.Calcium bicarbonate
3.Iron sulphide
Name two soluble nitrates which can be converted into insoluble chlorides by the use of dilute
HCl. Support your answer by chemical equations.
Q
Q
How will you convert iron to iron (II) chloride? Support your answer by a chemical equation. [2]
Q
Give a balanced equation for the thermal dissociation of a solid containing chloride ion.
Q
How will you obtain following from dil HCl acid? Give equations.
(a) Hydrogen (b) carbon dioxide
(c) sulphur dioxide (d) hydrogen sulphide
Q
Write an ionic equation when HCl gas dissolves in water. [1]
Q
Name an ion responsible for acidic nature of HCl acid.
Q
Give an equation for preparation of HCl gas by synthesis. State two conditions involved in its
synthesis. [2 + 1]
i.
ii.
iii.
Manganese (IV) oxide, lead (IV) oxide and red lead [Pb3O4] react with conc. HCl
liberating chlorine. (a) What is the common property being shown by these metal oxides.
(b) Write the equation for the reaction of conc. HCl with Pb3O4.
Write balanced equations for the reaction of manganese (IV) oxide and concentrated
hydrochloric acid.
Write the for the reaction of hydrochloric acid with manganese (IV) oxide.
Q
What is aqua regia? How does it help in dissolving gold or platinum? Support your answer with
chemical equations. [4]
Q.
A colourless gas G fumes strongly in air.The gas gives dense fumes when glass rod dipped in
ammonia solution is held near the gas.With reference to this answer the following questions
1. Name the gas G
2. Name the two chemicals used in preparation of gas G
3. Write the chemical equation for the chemicals named in 2.
When (i).The reaction mixture is not heated
(ii)When reaction mixture is heated above100*C
4. Why does the gas fumes in moist air
What do you observe whenQ
What will happen if I add sodium hypochlorite or sodium bisulfite to hydrochloric acid?
Q
What will happen if I add hydrochloric acid to sulfuric acid?
Q.
What would you see when hydrogen chloride mixes with ammonia.
Q
Answer the followingState what you observe when silver nitrate solution is added to dilute hydrochloric acid.
From the gases – ammonia, hydrogen chloride, hydrogen sulphide, Sulphur dioxide – Select
the following : The gas which gives a white ppt. when reacted with AgNO3 soln. acidified
with dilute nitric acid.
i.
ii.
Q
How does silver nitrate solution react with sodium chloride solution. State your observations
when above mixture is treated with excess of ammonium hydroxide. Support your answer by
chemical equations. [4]
Q
A solution of hydrogen chloride in water is prepared. The following substances are added to
separate portions of the solution :
S. No.
Substances added
1.
Calcium carbonate
2.
Magnesium ribbon
3.
Manganese (IV) oxide
with heating
4.
Sodium sulphide
Gas evolved
Odour
Complete the table by writing the gas evolved in each case and its odour.
Direct questions
Q
Compare the density of HCl gas with air. [1]
Q
Compare the solubility of HCl gas with water. [1]
Q
State the colour changes in three different indicators in the presence of HCl gas.
Q
Answer the following
(i) Hydrogen chloride dissolves in water forming an acidic solution. Name the experiment which
demonstrates that hydrogen chloride is very soluble in water.
(ii) Name the experiment illustrated by the figure given.
.
(iii)
(iv)
(a) Which property of hydrogen chloride is demonstrated by this experiment.
(bState the colour of the water that has entered
the round-bottomed flask.
Q
From the following list of substances – ammonium chloride, ammonium nitrate, chlorine, dilute
hydrochloric acid, iron, lead nitrate, manganese [IV] oxide, silver nitrate, sodium nitrate, Sulphur
– choose two compounds whose aq. solution give white precipitate with dil. HCl.
Q
What does fountain experiment explain about the nature of HCl gas. [1]
Q
Hydrogen chloride dissolves in water forming an acidic solution. Give three distinct tests [apart
from using an indicator] you would carry out with this solution to illustrate the typical properties
of an acid.
Q
Give two tests for HCl gas. [2]
Q
Give two tests for hydrochloric acid. [2]
Q
Q.
State four uses of hydrochloric acid. [2]
What property of hydrogen chloride is demonstrated when it is collected by downward
delivery[upward displacement of air].
Identify-A,B,C/X,Y Z Type questions
Q
Choose the chemicals from the letters A, B, C, D and E, which match the descriptions below
[A] NH4Cl [B] AgCl [C] Ag(NH3)2 Cl [D] PbCl2 [E]. FeCl2
(i) A salt which is soluble in hot water, but insoluble in cold water.
(ii) A salt which is insoluble in nitric acid, but soluble in ammonia solution.
(iii) A salt obtained when a basic gas reacts with HCl gas.
(iv) A salt obtained by the action of active metal with dil. HCl.
(v) A salt obtained by dissolving insoluble metallic chloride in excess of ammonium hydroxide.
Q
A colourless gas G fumes strongly in the air. The gas gives dense white fumes when a glass rod
dipped in ammonia solution is held near the gas. Answer the following questions :
(i) Name the gas G.
(ii) Name two chemicals used in the preparation of the gas G.
(iii) Write the chemical equations for the reaction of the chemicals named in (ii) when :
(a) The reaction mixture is not heated.
(b) The reaction mixture is heated above 100°C.
(iv) Why does the gas G fume strongly in air ?
(v) Why does the gas G form dense white fumes with ammonium hydroxide ? [5]
Q
(i) Hydrogen is burnt in a greenish-yellow gas A then another gas B is formed. The gas B gives
dense white fumes with ammonia liquor. Name the gases A and B. [2]
(ii) Write chemical equations in support of your answer in 32 (i). [2]
(iii) Burning sodium is taken in the gas B, when it forms a salt C and another colourless gas D.
The salt solution of C gives a curdy white precipitate with silver nitrate solution. The white
precipitate is soluble in excess of ammonium hydroxide.
(a) Name the salt C. [1]
(b) Name the gas D. [1]
Write the chemical equations for the reaction between
(1.) B and sodium (2.) C and silver nitrate
(3.) white precipitate and ammonium hydroxide [3]
Q
From the following gases – NH3, Cl2, HCl, SO2, select the gas that matches the description
given below and answer the questions that follow :
When gas C is mixed with gas B, dense white fumes are seen and there is no other product
[gas B turns moist red litmus paper blue]. (a) What is the name of gas C. (b) What is the
name of the product of the reaction between gas B and gas C.
Miscellaneous questions
Q
Describe tests (other than electrolysis) to prove that hydrochloric acid contains :
(i) hydrogen gas, (ii) chlorine gas
Q
What is the difference between hydrochloric acid and muriatic acid?
Q
Where does most of the hydrochloric acid produced come from?
Q
What materials are impervious to hydrochloric acid?
Q
What elements of chemistry are in hydrochloric acid?
HOT[ High Order Thinking]
Q
Q
Q
You enter a laboratory after a class has completed the fountain experiment .How will you be able
to tell whether the gas used in the experiment was hydrogen chloride or ammonia.[None of the gas
leaked in the lab during experiment
When hydrochloric acid comes in contact with common metals (i.e. Aluminum, iron, zinc), what
dangerous result can be expected?
Is it possible for hydrochloric acid to cause a fire if it isn't a flammable product?