What is the difference between skeletal equation and balanced chemical equation? Give example.

What is observed when:

(i) Potassium iodide is added to aqueous lead nitrate?

(ii) Identify the type of reaction.

(iii) Give a balanced chemical equation for this.

Marble statues often slowly get corroded when kept in open for a long time. Give a suitable explanation.

When a green iron salt is heated strongly, its colour finally changes to black and odour of burning sulphur is given out.

a. Name the iron salt.

b. Name the type of reaction that takes place during the heating of iron salt.

c. Write the balanced chemical equation for the reaction involved.

A, B and C are three elements which undergo chemical reactions according to the following equations.

A₂O₃ + 2B → B₂O₃ + 2A

3CSO₄ + 2B → B₂(SO₄)₃ + 3C

3CO + 2A → A₂O₃ + 3C

Answer the following questions with reasons.

a. Which element is the most reactive?

b. Which element is the least reactive?

c. What is the type of reactions listed above?