Question

A) The change in the internal energy of a system that absorbs 2,500 J of heat and that does 7,655 J of work on the surroundings is _________ J.

b) The ΔE of a system that absorbs 12.4J of heat and does 4.2 J of work on the surroundings is __________ J.

Answer 1

The change in internal energy of a system can be calculated using the equation ΔE = Q - W, where ΔE represents the change in internal energy, Q represents the amount of heat absorbed or transferred, and W represents the work done on or by the system.

Step-by-step explanation:

The change in internal energy of a system is given by the equation: ΔE = Q - W, where ΔE represents the change in internal energy, Q represents the amount of heat absorbed or transferred, and W represents the work done on or by the system.

(a) In this case, the system absorbs 2,500 J of heat and does 7,655 J of work on the surroundings. So, the change in internal energy is: ΔE = 2,500 J - 7,655 J = -5,155 J.

(b) In this case, the system absorbs 12.4 J of heat and does 4.2 J of work on the surroundings. So, the change in internal energy is: ΔE = 12.4 J - 4.2 J = 8.2 J.

Answer 2

Answers:

a) 10155 J

b) 16.6 J

Step-by-step explanation:

According to the First Law of Thermodynamics we have:

`\Delta E=Q + W`

Where:

`\Delta E` is the total change in the internal energy of a system

`Q` is the heat exchanged between the system and its surroundings

`W` is the work done on the system

a) In this case
`Q=2500 J` and
`W=7655 J`, hence:

`\Delta E=2500 J + 7655 J=10155 J`

b) In this case
`Q=12.4 J` and
`W=4.2 J`, hence:

`\Delta E=12.4 J + 4.2 J=16.6 J`