Question

If a system has 2.00 × 10 2 kcal 2.00×102 kcal of work done to it, and releases 5.00 × 10 2 kJ 5.00×102 kJ of heat into its surroundings, what is the change in internal energy of the system?

Answer 1

Answer:

336.8 kilo Joules is the change in internal energy of the system.

Explanation:

The equation for first law of thermodynamics follows:

$\Delta U=Q+W$

where,

Q = heat added to the system

ΔU = Change in internal energy

W = work done

We have :

Amount of heat given out by the system will be negatuive as heat relased by the system = Q

Q= $-5.00\times 10^2 kJ$

Work done on the system will positive as work is done on the system:

w = $2.00\times 10^2 kCal=836.8 kJ$

$\Delta U=-5.00\times 10^2 kJ+836.8 kJ=336.8 kJ$

336.8 kilo Joules is the change in internal energy of the system.