Chapter 8

Question 1

Thermodynamics

-thermochemistry

Answer 1

The study of energy and temperature changes

- energy changes in chemical reactions

Question 2

Energy is:

Answer 2

the ability to do work

Question 3

Forms of energy:

• Potential energy:
• Kinetic energy

Answer 3

• stored energy

- energy of motion

Question 4

Types of energy changes:

• Heat:
• Work:

Answer 4

• the transfer of kinetic energy

- the transfer of energy from one form to another

Question 5

1000 calories=

Answer 5

1 kcal = 1 Calorie

Question 6

1 calorie (c) =

Answer 6

4.184 J

Question 7

Change in energy:

Answer 7

ΔE = q+w (Total energy released = sum of heat (q) and work (w)

Question 8

Exothermic change

Answer 8

releases energy (sometimes depicted as +energy on the R side of a chemical equation)
releases heat energy: -q
system does work on surroundings: -w

Question 9

Endothermic change

Answer 9

Absorbs change (sometimes depicted as +energy on the L side of a chemical equation)
absorbs heat energy: +q
surroundings does work on system: +w

Question 10

In thermochemistry:

• The System:
• the surroundings:

Answer 10

• is the part of the universe being studied

- the rest of the universe

Question 11

The law of conservation of energy

Answer 11

Energy cannot be created or destroyed

ΔE system = -ΔE surroundings

Question 12

Heat energy and temperature

Answer 12

Heat: the t o t a l kinetic energy transferred from one object to another
Temperature: the a v e r a g e kinetic energy of the particles in a substance

Question 13

Specific heat

Answer 13

the relationship between heat mass and temp

the amount of heat required to raise the temperature of one gram of material by 1*C

Question 14

Equation for specific heat

Answer 14

specific heat = (heat)/ ((mass)x(change in temperature))
s=q/mΔT
q=msΔT

Question 15

Heat capacity, C

Answer 15

the amount of heat required to raise a substance by 1*C

Question 16

Heat capacity equation

Answer 16

heat capacity = q/ΔT

C= q/ΔT

Question 17

Calorimetry experiments

Answer 17

measure the flow of heat

Question 18

coffee cup calorimetry

Answer 18

q water = -q metal
(w and 2nd m’s are subscripts)
mwswΔTw=-mmsmΔTm

Question 19

fuel value

Answer 19

the amount of energy that can be produced by the combustion of a material
the higher the fuel value the more energy it releases when it burns

Question 20

reaction enthalpy

Answer 20

the amount of heat energy absorbed or released in a chemical reaction at a constant pressure
ΔHrxn
allows us to relate the heat changes in a reaction to the amount of any substance involved in the reaction.