Chemistry Equation

(i)
Marble chips contains mainly calcium carbonate. It is the property of acid that an acid solution can reacts with metal carbonate to give a salt, carbon dioxide and water.
CaCO3(s) + 2HNO3(aq) → Ca(NO3)2(aq) + H2O(l) + CO2(g)


(ii)
Dilute nitric acid is an oxidizing agent, while zinc is a reducing agent. Therefore, no hydrogen gas would be formed when dilute nitric acid and zinc react. Instead, a redox reaction occurs. Dilute Nitric acid is reduced to nitrogen monoxide, while zinc is oxidized to zinc ion.
3Zn(aq) + 8HNO3(aq) → 3Zn(NO3)2(aq) + 4H2O(l) + 2NO(g)
or: 3Zn(aq) + 8H+(aq) + 2NO3-(aq) → 3Zn2+(aq) + 4H2O(l) + 2NO(g)

1. CaCO3+HNO3->Ca(NO3)2+CO2+H2O
2. Zn+2HNO3->Zn(NO3)2+H2

u mean chemical equations?
Well, u can try with the word equations provided.
These 2 are very easy ones and u should know them well.

nitric acid + zinc = zinc nitrate + hydrogen
marble = calcium carbonate
nitric acid + calcium carbonate = calcium nitrate + carbon dioxide + water