Question

Diborane is a :
1. Colourless gas
2. Coloured gas
3. Toxic gas
4. Non-toxic gas

• A. 1, 2
• B. 1, 3
• C. 1,2,3
• D. 2, 4

Answer 1

The correct option is B 1, 3

Diborane is a colourless gas and highly toxic gas with boiling point 180 K.
Hence correct option is b.
Theory
Properties:
1. $B_2{H}_6$ is a colourless gas and highly toxic gas with a boiling point of 180 K.
2. Diborane catches fire spontaneously upon exposure to air.
$B_2{H}_6+3O_2\to B_2{O}_3+3H_{2}O$
${\Delta }_C{H}^{\circ }=–1976kJmo{l}^{–1}$
It burns in oxygen releasing an enormous amount of energy. Most of the higher boranes are also spontaneously flammable in the air.