Correct Answer - Option 1 :
\(\frac{7}{2}R\)
EXPLANATION:
The molar specific heat capacity of a gas at constant volume is defined as the amount of heat required to raise the temperature of 1 mol of the gas by 1 °C at the constant volume.
\({C_v} = {\left( {\frac{\Delta Q}{{n\Delta T}}} \right)_{\rm constant\;volume}}\)
- The molar specific heat of a gas at constant pressure is defined as the amount of heat required to raise the temperature of 1 mol of the gas by 1 °C at the constant pressure.
\({C_p} = {\left( {\frac{{\Delta Q}}{{n\Delta T}}} \right)_{\rm constant\;pressure}}\)
- The ratio of the two principal specific heat is represented by γ.
\(\therefore \gamma = \frac{{{C_p}}}{{{C_v}}}\)
- The value of γ depends on the atomicity of the gas.
- For monoatomic gas,
\(C_P = \frac{5}{2} R\)
\(C_P = \frac{7}{2} R\)
- Therefore, option 1 is correct.
-
Specific heat capacity at constant volume (CV): It is the amount of heat required to raise the temperature of 1 kg of gas maintained at constant volume by 1 degree Celcius.
- Specific heat capacity at constant volume (CV) for monoatomic gas is,
\(C_V = \frac{3}{2} R\)
- Specific heat capacity at constant volume (CV) for for diatomic gas,
\(C_V = \frac{5}{2} R\)