Question

Calculate the speed of sound in oxygen from the following data. The mass of 22.4 litre of oxygen at STP $(T=273KandP=1.0\times {10}^{5}N{m}^{-2})$ is 32g, the molar heat capacity of oxygen at constant volume is $C_V$ = 2.5 R and that at constant pressure is Cp = 3.5 R.

• A. 300m/s
• B. 315m/s
• C. 350m/s
• D. 365m/s

Answer 1

The correct option is B

315m/s

The mass of 22.4 L of any ideal gas at STP = molecular mass.

Considering oxygen to be ideal

M${}_{Oxygen}$ = 32 g

C${}_V$ = 2.5 R, C${}_P$ = 3.5 R (given)

V${}_1$ speed of sound in

$O_2=\sqrt{\frac{\gamma RT}{M}}$

$\sqrt{\frac{\left(\frac{C_P}{C_V}\right).R.273}{32\times {10}^{-3}}}$

$=315\frac{m}{s}$