10.3 Enthalpy and Enthalpy Changes

Question 1

enthalpy (H)

Answer 1

a measure of the total energy of a system; the sum of the internal energy and the pressure•volume product of a system

Question 2

equation for enthalpy

Answer 2

H= E(energy) + PV

Question 3

enthalpy change (🔺H)

Answer 3

the energy absorbed by an endothermic process or given off by an exothermic process that takes place at constant pressure

Question 4

equation for enthalpy at constant pressure

Answer 4

🔺H=🔺E+P🔺•V

Question 5

enthalpy of fusion (🔺H fus)

Answer 5

the energy required to convert one mole of a solid substance at its melting point into the liquid state: also called the heat of fusion

Question 6

enthalpy of vaporization (🔺H vap)

Answer 6

the energy required to convert one mole of a liquid substance at its boiling point into the vapor state; also called the heat of vaporization.

Question 7

+delta H (H initial low, H final high)

Answer 7

endothermic

Question 8

-delta H (high H inital, low H final)

Answer 8

exothermic