Question

$P{H}_3$ produces smoky rings when it comes in contact with air. This is because:

• A. It is inflammable
• B. It combines with water vapour
• C. It combines with nitrogen
• D. It contains impurity of $P_2{H}_6$

Answer 1

The correct option is D It contains impurity of $P_2{H}_6$

$P{H}_3$ frequently contains traces of $P_2{H}_6$ which cause it to catch fire spontaneously. This is the origin of the flickering light called will-o-the-wisp, which is sometimes seen in marshes.