Question

If one monoatomic gas is expanded adibatically from $2L$ to $10L$ at 1 atm external pressure then the value of $\Delta U$ (in atm L) is

• A. -8
• B. 0
• C. -66.7
• D. 58.2

Answer 1

The correct option is A -8

For adiabatic process, no heat is transfered between the system and surrounding, hence,
Q = 0

$\therefore \Delta U=Q=-P_{ext}\Delta V$
$=-1(10-2)atmL\Delta U=-8L$