Question

Write balanced equations and name the products formed when: [4 MARKS]
(a) sodium hydrogen carbonate is added to nitric acid,
(b) cupric oxide reacts with nitric acid,
(c) zinc reacts with dilute nitric acid,
(d) concentrated nitric acid is heated.

Answer 1

Each Part: 1 Mark

(a) When sodium hydrogencarbonate is added to nitric acid, it forms salt, water and carbon dioxide.
$NaHC{O}_3+HN{O}_3\to NaN{O}_3+H_{2}O+C{O}_2\uparrow$

(b) When cupric oxide reacts with nitric acid, copper nitrate is formed.
$CuO+2HN{O}_3\to Cu(N{O}_3{)}_2+H_{2}O$

(c) Zinc reacts with dilute nitric acid to form nitrous oxide.
$4Zn+10HN{O}_3(dil.)\to 4Zn(N{O}_3{)}_2+N_{2}O+5H_{2}O$

(d) When conc. nitric acid is heated, it rapidly decomposes to form reddish brown nitrogen dioxide gas, water and oxygen.
$4HN{O}_3\underrightarrow{\Delta }2H_{2}O+4N{O}_2\uparrow +O_2\uparrow$