Question

A highly reactive element (X) reacts with oxygen of air even at room temperature to give an oxide (Y). The oxide (Y) is soluble in water. The aqueous solution of (Y) does not change color of red litmus solution but reacts with an aqueous solution of sodium hydroxide. The $\left(X\right)$ is:

• A. Sodium
• B. Phosporous
• C. Carbon
• D. Sulphur

Answer 1

Answer: (B), (D)

The correct options are
B Phosporous
D Sulphur

The highly reactive element is either $S$ or $P$. It reacts with oxygen of air even at room temperature to give an oxide .
$S+O_2\to S{O}_2$
$P_4+5O_2\to P_4{O}_{10}$
Oxide is soluble in water. The aqueous solution of oxide does not change color of red litmus solution but reacts with an aqueous solution of sodium hydroxide. This indicates that the oxide is acidic oxide. Hence, the options B and D are correct answers.