Question

	Appearance	Reaction with dilute $HCl$	Reaction with dilute $HN{O}_3$
Unknown metal #1	Dull gray solid with white oxide coating	Dissolved with bubbles of clear gas	Dissolved with bubbles of clear gas
Unknown metal #2	Solid; lustrous, smooth silver-gray surface	No reaction	Dissolved with bubbles of orange gas

Identify the orange gas produced on the addition of dilute $HN{O}_3$ to unknown metal #2.

• A. ${Cl}_2$
• B. $H_2$
• C. $O_2$
• D. $C{O}_2$
• E. $N{O}_2$

Answer 1

The correct option is E $N{O}_2$

Silver has a lustrous smooth gray surface.

It reacts with $HN{O}_3$ as;

$3Ag+2{HNO}_3\to {4AgNO}_3+{NO}_2+H_{2}O$.

Thus the orange gas produced is $N{O}_2$.