Question

The speed of sound in hydrogen at NTP 1270 m/s. Then, the speed in a mixture of hydrogen and oxygen in the ratio 4 : 1 by volume will be :

• A. 317 m/s
• B. 635 m/s
• C. 830 m/s
• D. 950 m/s

Answer 1

The correct option is B 635 m/s

The volume of hydrogen and oxygen in a mixture is 4 : 1. So let V be the volume of oxygen. The volume of hydrogen will be 4V if ${\rho }_m$ be the density of mixture, then
${\rho }_m=\frac{4V\times 1+V\times 1}{5V}=4$
$V\infty {\left(\frac{1}{\rho }\right)}^{1/2}$
Velocity in mixture $=\frac{1270}{(4{)}^{3/2}}=635m/s$