Question

A container is filled with 20 moles of an ideal diatomic gas at absolute temperature T. When heat is supplied to gas temperature remains constant but 8 moles dissociate into atoms. Heat energy given to gas is

• A. 4 RT
• B. 6 RT
• C. 3 RT
• D. 5 RT

Answer 1

Answer: (A)

4 RT

Initial energy$=\frac{t}{2}nRT=\frac{5}{2}\times 20\times RT=50RT$

Field energy $=(\frac{5}{2}\times 12RT)+(\frac{3}{2}\times 16RT)=30RT+24RT=54RT$

Heat supplied$=$ Increase in energy

$=4RT$