Question

A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37.0⁰C. As it does so, it absorbs 208 J of heat. The values of q and w for the process will be:

(R = 8.314 J/mol K) (ln 7.5 = 2.01)

• A. q = +208 J, w = – 208 J
• B. q = –208 J, w = – 208 J
• C. q = –208 J, w = + 208 J
• D. q = +208 J, w = + 208 J

Answer 1

Answer: (A)

q = +208 J, w = – 208 J

Answer 2

The process is isothermal expansion Hence, q = - w

$\Delta$u = 0

q = + 208 J

w = - 208 J(expansion work)