Question

Gases A and B are confined to a cylinder and piston and react to form product C. As the reaction occurs, the system loses 1189 J of heat to surroundings. The piston moves downward as the gases react to form a solid. As the volume of the gas decreases under the constant pressure of the atmosphere, the surroundings do 311 J of work on the system. What is the change in the internal energy of the system

Answer 1

The change in the internal energy of the system -878 J

Step-by-step explanation:

Given;

energy lost by the system due to heat, Q = -1189 J (negative because energy was lost by the system)

Work done on the system, W = -311 J (negative because work was done on the system)

change in internal energy of the system, Δ U = ?

First law of thermodynamics states that the change in internal energy of a system (ΔU) equals the net heat transfer into the system (Q) minus the net work done by the system (W).

ΔU = Q - W

ΔU = -1189 - (-311)

ΔU = -1189 + 311

ΔU = -878 J

Therefore, the change in the internal energy of the system -878 J