A metal X (used for galvanization) is immersed in the aqueous solution of a blue salt YSO₄. Metal Y is deposited on the surface of the solution and a strip of metal X dissolves.

(a) Predict the metal X.

(b) What type of reaction is it?

(c) Write the word equation for this reaction and balance it.

State the main characteristics of chemical reactions. Give at least one example in each case.

Complete and balance the following reactions:

(a) NaCl (aq.) + AgNO₃ (aq.) ⟶

(b) Pb(NO₃)₂ + KI ⟶

(c) CuCO₃ $\xrightarrow{\Delta}$

(d) Pb(NO₃)₂ $\xrightarrow{\Delta}$

(e) CO₂ + H₂O $\xrightarrow[\text{sunlight}]{\text{Chlorophyll}}$

What do you observe in the following cases?

(a) Lead nitrate is heated.

(b) Silver chloride is exposed to sunlight.

(c) Hydrogen peroxide is exposed to sunlight

(d) H₂S gas is passed through copper sulphate solution

(e) Barium chloride is added to sodium sulphate solution.

(f) Water is added to quick lime

(g) Sodium chloride solution is added to silver nitrate solution.