The ratio of densities of nitrogen and oxygen is 14 : 16. The temperat...
p p TN=287K=14∘C
The ratio of densities of nitrogen and oxygen is 14 : 16. The temperat...
Given Data:
- The ratio of densities of nitrogen and oxygen is 14 : 16.
- The temperature at which the speed of sound in nitrogen will be the same as that of oxygen is 55°C.
Approach:
- The speed of sound in a gas is given by the formula: v = √(γRT), where γ is the adiabatic index, R is the gas constant, and T is the temperature.
- Since the speed of sound is directly proportional to the square root of temperature, we need to find the temperature at which the speed of sound in nitrogen equals the speed of sound in oxygen.
Solution:
- Let's assume the speeds of sound in nitrogen and oxygen at 55°C are vN and vO respectively.
- Given that the ratio of densities of nitrogen and oxygen is 14 : 16, we can write: (ρN/ρO) = (16/14) = (vO/vN)^2, where ρ is the density.
- Since the densities are proportional to the molecular weights of the gases, we have: (Molecular weight of O/Molecular weight of N) = (vO/vN)^2.
- As the molecular weights of nitrogen and oxygen are 28 and 32 respectively, we get: (32/28) = (vO/vN)^2.
- Solving for vO/vN, we get vO/vN = √(32/28) = √(8/7).
- To find the temperature at which vO = vN, we need to square this ratio: (vO/vN)^2 = (8/7).
- Therefore, the temperature at which the speed of sound in nitrogen will be the same as that of oxygen is 14°C (Option D).