Logarithms of readings of pressure and volume for an ideal gas were plotted on a graph as shown in Fig. By measuring the gradient, it can be shwon that the gas may be

Options

A. monatomic and undergoing an adiabatic change
B. monatomic and undergoing an isothermal change
C. diatomic and undergoing an adiabatic change
D. triatomic and undergoing an isothermal change

Answer

C

Explanation

c. `log P = m log V + C_(1)`, where `C_(1)` is positive, `m` is slope
`m = (2.38 - 2.10)/(1.1 - 1.3) = 1.4`
`log P = 1.4 log V + C_(1)`
`log PV^(1.4) = C_(1)`
`PV^(1.4) = k`
Thus, it represent an ideal diatomic gas undergoing adiabatic change.