Calculate the change in internal energy for a gas using the first law of thermodynamics. The gas transfers 485 J of energy as heat to the surroundings.

P_{ext} = 1.01 x 10^{5} Pa

V_{1} = 2.30 L

V_{2} = 2.05 L

For a gas, the **internal energy** (**Δ****E or ****Δ****U**) of a system can be calculated from the **heat **and **work **of the system.

The relationship between internal energy, heat, and work is shown in the following equation:

$\overline{){\mathbf{\u2206}}{\mathbf{E}}{\mathbf{=}}{\mathbf{q}}{\mathbf{+}}{\mathbf{w}}}$

Where

ΔE = internal energy, J

q = heat, J

w = work, J

**To solve for Internal Energy, we have to:**