Chapter 5: Enthalpy and Energy

Question 1

Define enthalpy

Answer 1

Is a measure of the total energy of a thermodynamic system. It includes the system’s internal energy, which is one of five common thermodynamic energy potentials and a state function, as well as its volume and pressure

Question 2

Define “heat”

Answer 2

Heat is the energy transferred from a hotter object to a colder object

Question 3

Thermochemistry terms to know: ΔE=q+w

Define the terms

Answer 3

Q=Heat

W=Work

Question 4

What else does W=?

Answer 4

w=−PΔV
Pressure, Volume

However, this is in L/m, and must be converted into kilojoules in order to work for
ΔE=ΔH−PΔV

Question 5

What else does W=?

Answer 5

w=−PΔV
Pressure, Volume

However, this is in L/m, and must be converted into kilojoules in order to work for
ΔE=ΔH−PΔV

Question 6

The change in internal energy, ΔU, is _______ if the system absorbs energy, and it is ________ if the system releases energy. (Figure 1) The total change in internal energy is the sum of the ____, q, and ____, w: ΔU=q+w.

Answer 6

Positive, negative, heat, work