Question

calculate the change in internal energy, in kj, for a system that absorbs 1.72x10^4 j of heat and does 4.08x10^4 j of work on the surroundings. report your answer to the first place after the decimal point.

Explanation:

Step1: Recall the first law of thermodynamics formula

The first law of thermodynamics is $\Delta U=Q - W$, where $\Delta U$ is the change in internal energy, $Q$ is the heat added to the system, and $W$ is the work done by the system.

Step2: Substitute the given values

Given $Q = 1.72\times10^{4}\text{ J}$ and $W=4.08\times 10^{4}\text{ J}$. Then $\Delta U=(1.72\times 10^{4})-(4.08\times 10^{4})\text{ J}$.

Step3: Calculate the value

$\Delta U=(1.72 - 4.08)\times10^{4}\text{ J}=- 2.36\times10^{4}\text{ J}$. Convert to kJ: $\Delta U=-23.6\text{ kJ}$ (since $1\text{ kJ} = 10^{3}\text{ J}$)

Answer:

$-23.6\text{ kJ}$