Question

	Appearance	Reactions 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

The addition of dilute $HN{O}_3$ to unknown metal # $2$ produced an orange gas. What is the likely identity of this gas?

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

Answer 1

Answer: (D)

$N{O}_2$

The metal with grey color surface and lustrous is silver.

Silver reacts only with $HN{O}_3$ to form a salt and forms clear gas of $N{O}_2$. Ag do not react with $HCl$

$2HN{O}_3+2Ag\to 2AgN{O}_3+N{O}_2+H_{2}0$.

Hence option A is correct.Hence option D is correct.