Question

When the amount of work done on the system is 333 cal and the change in internal energy is 167 cal, then the magnitude of heat associated with the process is:

• A. 166 cal
• B. 333 cal
• C. 500 cal
• D. 400 cal

Answer 1

The correct option is A 166 cal

According to first law of thermodynamics,
$Q=△U-W$
Where $Q$ = Heat given to the system
$△U$ = Change in internal energy
$W$ = Work done on the system
Given $W$ = + 333 cal and $△U$ = +167 cal
$Q=△U-W=167-333=-166$ cal
and magnitude of heat = $166$ cal