Laboratory Preparation Method

Q. Solution A is a strong acid.
Solution B is a weak acid.
Solution C is a strong alkali.
(i) Which solution contains solute molecules in addition to water molecules?
(ii) Which solution will give a gelatinous white precipitate with zinc sulphate solution? The precipitate disappears when an excess of the solution is added.
(iii) Which solution could be a solution of glacial acetic acid?
(iv) Give an example of a solution which is a weak alkali.

Q.

What is brisk effervescence?

Q.

The chemical formula for ferrous sulphate heptahydrate is _____

Q. Give reasons :

1. In the laboratory preparation of HCL acid from NACL and conc H2SO4 , the residual salt formed at temperatures above 200 °C forms a hard crust and stick to the glass. [2]

2. In the fountain experiment to demonstrate the high solubility of HCL gas in water , dry HCL gas is filled in the round bottom flask. [2]

Q.

Why ${\mathrm{SO}}_3$ is not added directly to the water?

Q.

What happens to the colour of bromine water when $S{O}_2$ is passed into the solution?

1. The orange brown color fades away

2. The color remains the same

3. Orange brown solution tuns to green

4. Orange brown solution turns to yellow

Q. Salts A, B, C, D and E undergo reactions (i) to (v) respectively. Identify the anion present in these salts on the basis of these reactions. Tabulate your answers in the format given below:
(i) When silver nitrate solution is added to a solution of A, a white precipitate, insoluble in dilute nitric acid, is formed.
(ii) Addition of dilute hydrochloric acid to B produces a gas which turns lead acetate paper black.
(iii) When a freshly prepared solution of ferrous sulphate is added to a solution of C and concentrated sulphuric acid is gently poured from the side of the test tube, a brown ring is formed.
(iv) When dilute sulphuric acid is added to D, a gas is produced which turns acidified potassium dichromate solution from orange to green.
(v) Addition of dilute hydrochloric acid to E produces an effervescence. The gas produced turns limewater milky but does not affect acidified potassium dichromate solution.

Salt	Anion
A
B
C
D
E

Q.

Describe the reactions that show
(i) Concentrated sulphuric acid is a non-volatile acid.
(ii) Concentrated sulphuric acid acts as a dehydrating agent.
(iii) Concentrated sulphuric acid is an oxidising agent.
(iv) Dilute sulphuric acid behaves as dibasic acid.

Q.

CuO + H₂SO₄ → CuSO₄ + H₂O is an example of which property of the sulphuric acid?

1. Acid

2. Dehydrating agent

3. Non-volatile acid

4. Oxidizing agent

Q.

Give the chemical formula of :

1. Bauxite
2. Cryolite
3. Sodium aluminate

Q.

An alkaline gas A gives dense white fumes with hydrogen chloride. What is A?

1. NH₃

2. Cl₂

3. SO₂

4. H₂S

Q.

Correct the following statement:
Hydrochloric acid is prepared in the laboratory by passing hydrogen chloride directly through water.

Q.

State the observation when:
(i) ethylene gas is bubbled through bromine water.
(ii) a piece of sodium is dropped into ethyl alcohol.
(iii) acetylene gas is burnt in air.
(iv) an acidified solution of potassium dichromate is added to ethyl alcohol.

Q. Which of the following molecule(s) gives only acid(s) or acidic species on hydrolysis?

1. $PC{l}_3$
2. $S{F}_4$
3. $NC{l}_3$
4. $P_4{O}_6$

Q.

What is the molecular formula of silver glance?

1. ${\mathrm{Ag}}_2\mathrm{S}$

2. $\mathrm{AgCl}$

3. ${\mathrm{CaCO}}_3$

4. ${\mathrm{Al}}_2{\mathrm{O}}_3$

Q.

Which of the following gases when dissolved in aqueous solution of SO₂ give sulphuric acid as a product?

1. Hydrogen gas

2. Oxygen gas

3. Chlorine gas

4. Bromine

Q.

Give two examples of strong acids.

Q.

What would you observe in the following case:
Sugar crystals are added to hard glass test tube containing concentrated sulphuric acid.

Q.

What happens when SO₂ gas is mixed with water?

Q.

______ is obtained by distilling conc. sulphuric acid with potassium nitrate.

1. Phosphoric acid

2. Nitric acid

3. Perchloric acid

4. Hydrochloric acid

Q.

Which of the following give two acids as products?

1. Sulphur dioxide and bromine water

2. Sulphur dioxide and flourine water

3. Sulphuryl chloride with water

4. Sulphur with conc nitric acid

Q.

Sulphuric acid can be prepared by reacting Sulphur with

1. Potassium dichromate solution

2. Potassium permanganate

3. Dilute nitric acid

4. Concentrated nitric acid

Q.

Why conc. sulphuric acid is not used to dry hydrogen?

Q.

Why conc. sulphuric acid is not used to dry hydrogen?

Q. Addition of nitric acid to acidified $FeS{O}_4$ serves as a test for the former gives :

1. ferrous sulphate solution (brown black)
2. ferrous sulphate solution (brown)
3. ferrous sulphate solution (black)
4. ferrous sulphate solution (green)

Q. Answer the following: [5 MARKS]
(a) What is the composition of saturated solution of hydrogen chloride gas in water?
(b) What do you see when conc. hydrochloric acid is added to lead(IV) oxide with warming?
(c) What must be added to must be added to sodium chloride to obtain hydrogen chloride?
d) What do you see when hydrogen chloride mixes with ammonia?

Q.

Select the option which is a property of sulphuric acid?

1. Sulphuric acid has a strong affinity for water

2. It is a good hydrating agent

3. Sulphuric acid is a good reducing agent

4. It turns wet red litmus into blue colour

Q.

Sulphuric acid can be prepared in the lab by dissolving ___ in water.

Q.

Which of these is the key compound for the laboratory preparation of sulphuric acid?

1. Sulphur dioxide

2. Sulphur trioxide

3. Nitric oxide

4. Sulphur monoxide

Q.

Fill in the blank spaces by choosing the correct words from the given list.

List: Oxygen, carbonic, sulphur dioxide gas, precipitation, helium

Solution of carbon dioxide in water is called ________ acid.