Chem- chapter 5

Specific heat capacity

the amount of energy needed to change 1 g of a substance by 1 °C.

Specific heat of water

4\.18

Calorimetry

the accurate and precise measurements of heat changes for chemical and physical processes.

Endothermic

process that absorbs energy

Exothermic

process that releases energy

enthalpy

the heat content for systems at a constant pressure (represented as H).

thermometer

instrument used to measure average kinetic energy

joule

SI unit for energy

calorie (lowercase c)

one calorie is the amount of energy needed to raise 1 g of water by 1 °C

kinetic energy

the energy of motion

potential energy

stored energy or energy of position

solid

1

liquid

3

gas

5

endothermic

Type of process

Reactants

A

Products

B

Heat change (delta H)

C

x-axis label

Reaction

y-axis label

Potential Energy

exothermic

Type of process?

1 Cal= 0.00418 J

Cal to Joules

1 cal= 4.18 J

cal to Joules

1000 cal= 1 Cal

cal to Cal

H°f

standard heat of formation

Standard temperature (STP)

0° C

Standard pressure (STP)

1 atm or 101.3 kPa

Law of conservation of energy

energy cannot be created nor destroyed

Temperature

the measurement of average kinetic energy

Work

moving matter against an opposing force

Energy

the capacity to do work

Thermochemistry

the study of heat changes that occur during chemical reactions and physical changes of state.

Heat capacity

the amount of energy needed to change the temperature of an object by 1 °C.

Calorimeter

device used to measure the heat absorbed or given off.

Thermochemical reactions

an equation including heat change (NOT q=mcAT).

Heat of reaction

the heat change for an equation as written.

molar heat of combustion

energy change when burning one mole of a substance.

molar heat of fusion

energy change when melting one mole of a substance.

Molar heat of solidification

energy change when freezing one mole of a substance.

molar heat of vaporization

energy change when vaporizing one mole of a substance.

molar heat of condensation

energy change when condensing (changing from gas to liquid) one mole of a substance.

molar heat of solution

energy change per mole of solute when making a solution.

heating curve

represents heat vs. temp.

vaporization

4 (pink)

condensation

4 (green)

solidification

2 (green)

melting

2 (pink)

Chemical potential energy

energy stored in chemicals because of their compositions