Reaction of Metals with Dil. Sulphuric Acid

Q.

Define oxidation.

Q.

Describe with a suitable diagram the Deacon process of manufacturing chlorine. Write its reaction with ammonia.

Q.

Write the balanced chemical equation for the following reaction.

Gold added to aqua-regia.

Q.

Reaction of sulphuric acid with zinc oxide results in formation of salt and hydrogen.

1. True

2. False

Q.

Copper does not react with conc. sulphuric acid but reacts with the dilute acid

1. True

2. False

Q. Why does zinc react with sulphuric acid to give hydrogen age but copper does not?

Q.

Write the type of reactions in the following:
i. Reaction between an acid and a base
ii.Rusting of iron

Q.

Identify the reducing agent and oxidizing agent in the following reactions:

$2\mathrm{Mg}+{\mathrm{O}}_2\to 2\mathrm{MgO}$

Q.

What happens when zinc oxide reacts with hydrochloric acid?

1. Zinc hydroxide is formed.

2. Zinc hydroxide and hydrogen is formed.

3. Zinc chloride and water is formed.

4. Zinc chloride and hydrogen is formed.

Q. What do you understand by redox reactions? Explain oxidation and reduction in terms of loss or gain of electrons.

Q.

Write the balanced equations for the preparation of the following salts in the laboratory :

(a) A soluble sulphate by the action of an acid on an insoluble base,

(b) An insoluble salt by the action of an acid on another salt,

(c) An insoluble base by the action of a soluble base on a soluble salt,

(d) A soluble sulphate by the action of an acid on a metal.

Q.

A substance which oxidises itself and reduces other is known as

1. an oxidising agent

2. a reducing agent

3. Both of these

4. None of these

Q.

What are the salts of sulphuric acid called?give one example of such salt

Q.

Making use only of substances chosen from those given below:

Dilute sulphuric acid Zinc Lead

sodium carbonate sodium sulphite calcium carbonate

Give the equations for the reactions by which you could obtain:
(i) hydrogen
(ii) sulphur dioxide
(iii) carbon dioxide
(iv) zinc carbonate (two steps required).

Q.

Select the acid responsible for the sour taste in oranges and lemons.

1. Oxalic acid

2. Tartaric Acid

3. Citric Acid

4. Carbonic Acid

Q.

Name the constituents of German silver.

Q.

Identify the reducing agent and oxidizing agent in the following reactions:

${\mathrm{V}}_2{\mathrm{O}}_5+5\mathrm{Ca}\to 2\mathrm{V}+5\mathrm{CaO}$

Q. 5. Why Na2HPO4 is an acid salt but NA2HPO3 is a normal salt?

Q.

In the reaction $\mathrm{Mg}+{\mathrm{Cl}}_2\to {\mathrm{MgCl}}_2$, Chlorine may be regarded as:

1. an oxidizing agent

2. a reducing agent

3. a catalyst

4. providing an inert medium

Q.

Identify the reducing agent and oxidizing agent in the following reactions:

$4{\mathrm{NH}}_3+5{\mathrm{O}}_2\to 4\mathrm{NO}+6{\mathrm{H}}_2\mathrm{O}$

Q.

In which of the following reactions is sulphur dioxide released?

1. Oxidation of C by conc. sulphuric acid

2. Copper with conc. sulphuric acid

3. Zinc with dilute sulphuric acid

4. Oxidation of S by conc. nitric acid

Q. (a) When carbon is heating with concentrated sulphuric acid, carbon dioxide is formed. Why?
(b) Why the wooden shelves on which concentrated sulphuric acid bottles are kept are stained black? [4 MARKS]

Q.

Which of the following is a redox reaction?

1. ${\mathrm{CaCO}}_3\to \mathrm{CaO}+{\mathrm{CO}}_2$

2. ${\mathrm{H}}_2+{\mathrm{Cl}}_2\to 2\mathrm{HCl}$

3. $\mathrm{CaO}+2\mathrm{HCl}\to {\mathrm{CaCl}}_2+{\mathrm{H}}_2\mathrm{O}$

4. $\mathrm{NaOH}+\mathrm{HCl}\to \mathrm{NaCl}+{\mathrm{H}}_2\mathrm{O}$

Q.

Write a balanced equation for a reaction in which ammonia is oxidized by:

1. Metal oxide
2. A gas which is not oxygen.

Q.

What is the name given to the salts of :

(a) sulphurous acid, (b) sulphuric acid ?

Q.

Sulphuric acid forms two types of salt when reacted with sodium hydroxide in different conditions.

Q.

In the reaction, ${\mathrm{P}}_4+\mathrm{NaOH}+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{PH}}_3+{\mathrm{NaH}}_2{\mathrm{PO}}_2$ the mole ratio of ${\mathrm{NaH}}_2{\mathrm{PO}}_2$ and ${\mathrm{PH}}_3$ is :

Q.

The chemical reaction in which loss and gain of electrons takes place is called _______

Q.

A redox reaction is one in which

1. both the substances are reduced.

2. both the substances are oxidised.

3. an acid is neutralised by the base.

4. one substance is oxidised, while the other is reduced.

Q.

The process in which the surface of the metals is cleaned by a chemical is called

1. leeching

2. galvanization

3. pickling

4. reduction