(a) Suggest how the following liquid reagents can be suitably stored in the laboratory   

(i) X which fumes in moist air; 

(ii) Y which is slowly decomposed by sunlight in ordinary reagent bottles.

(b) State what is observed when aqueous ammonia is added to:

(i) litmus paper;

(ii) Pb(NO\(_3\))\(_2\) solution in drops until in excess

(iii) freshly precipitated AgCI in excess.

(c) A salt sample was suspected to be either Na\(_2\)CO\(_2\) or NaHCO\(_3\). A student who was required to identify it tested a portion for solubility in water and then for effect on litmus paper.

(i) What was observed in each case?

(ii) Give the reason why the student's procedure was unsuitable

(iii) Describe briefly how you would have identified the salt.