Question

Find ΔE

   a. when 175 J of work is done on a system that evolves 50 J of heat to the surroundings

   b. when a gas absorbs 28 kJ of heat and has 13 kJ work done on it

Answer 1

Solution.

$a)\Delta\Epsilon=A-Q;$

$\Delta E=175J-50J=125J;$

$b)\Delta E=Q-A;$

$\Delta E=28kJ-13kJ=15kJ;$

Answer: $a)\Delta E=125J;$

$b)\Delta E=15kJ.$