Understanding Internal Energy Changes

What is the relationship between the total energy change of a system and the changes in heat and work?

• The total energy change is unrelated to changes in heat and work.

• The total energy change is the product of changes in heat and work.

• The total energy change is the difference between changes in heat and work.

• The total energy change is the sum of changes in heat and work.

If a system releases heat, what is the sign of Q?

• Positive

• Negative

• Zero

• It depends on the amount of heat released.

When a system absorbs heat from its surroundings, what happens to the value of Q?

• Q becomes negative.

• Q becomes positive.

• Q remains zero.

• Q becomes undefined.

If a system does work on its surroundings, what is the sign of W?

• Negative

• Positive

• It depends on the amount of work done.

• Zero

What is the sign of W when work is done on the system by the surroundings?

• It depends on the system.

• Positive

• Zero

• Negative

In the formula Delta E = Q + W, what does Delta E represent?

• The change in temperature of the system.

• The change in internal energy of the system.

• The change in volume of the system.

• The change in pressure of the system.

A gas absorbs 54 kJ of heat and does 29 kJ of work. What is the change in the system's energy?

• -25 kJ

• -83 kJ

• 25 kJ

• 83 kJ

If a system releases 135 kJ of heat and has 110 kJ of work done on it, what is the change in energy?

• -245 kJ

• -25 kJ

• 25 kJ

• 245 kJ

A system absorbs 55 kJ of heat and has 142 kJ of work done on it. What is the total energy change?

• -87 kJ

• -197 kJ

• 87 kJ

• 197 kJ

What does a negative Delta E indicate about a system's process?

• The process is endothermic.

• The process is exothermic.

• The process is isothermal.

• The process is adiabatic.