Question

Figure shows the variation in temperature ($\Delta$T) with the amount of heat supplied $(Q)$ in an isobaric process corresponding to a monoatomic $(M)$, diatomic $(D)$ and a polyatomic $(P)$ gas. The initial state of all the gases are the same and the scales for the two axes coincide. Ignoring vibrational degrees of freedom, the lines a, b and c respectively correspond to :

• A. P, M and D
• B. M, D and P
• C. P, D and M
• D. D, M and P

Answer 1

Answer: (B)

On giving same amount of heat at constant pressure, there is no change in temperature for mono, dia and polyatomic.
$
(\Delta Q )_{ P }=\mu C _{ p } \Delta T \left(\mu=\frac{\text { No. of molecules }}{\text { Avogedro's no. }}\right)
$
$
\text { or } \Delta T \propto \frac{1}{\text { no. of molecules }}
$