THERMOCHEMISTRY

Question 1

Kinetic energy

Answer 1

Energy associated with motion (thermal)

Question 2

Potential energy

Answer 2

Energy associated with position (chemical)

Question 3

Kinetic energy formula

Answer 3

KE = 1/2mv^2

Question 4

System

Answer 4

Set of substances and energy being studied

Question 5

Surroundings

Answer 5

Everything else not part of the system

Question 6

3 types of system

Answer 6

• Open system: Exchange of energy and matter
• Closed system: Exchange of energy
• Isolated system: No exchange

Question 7

First law of thermodynamics

Answer 7

States that energy can neither be created or destroyed, only altered in form

Question 8

Internal energy

Answer 8

Sum of potential and kinetic energy (Delta U = q + w)

Question 9

Heat (q)

Answer 9

Transfer of thermal energy between system and surroundings caused by temperature difference

Question 10

Thermal equlibrium

Answer 10

Occurs when heat transfer stops

Question 11

+q

Answer 11

Absorbs heat (endothermic)

Question 12

-q

Answer 12

Releases heat (exothermic)

Question 13

What type of system is a calorimeter

Answer 13

Isolated

Question 14

+w

Answer 14

On the system

Question 15

-w

Answer 15

By the system

Question 16

Chemical reactions in solution in a calorimeter

Answer 16

qrxn = -Csoln msoln DeltaTsoln

Question 17

Chemical reactions not in solution

Answer 17

qrxn = -Ccal mcal DeltaTcal

Question 18

Relationship between system and surroundings

Answer 18

Inversely proportional. If system gains 300J, then surrounding loses 300J

Question 19

Work (w)

Answer 19

Product of force and distance

Question 20

Work formula

Answer 20

W = -P DeltaV OR -Deltan RT

Question 21

State function

Answer 21

Property whose values dont depend on the pathway taken (internal energy)

Question 22

Pathway function

Answer 22

Property whose values depend on the pathway taken (heat and work)

Question 23

Bomb calorimeter

Answer 23

Constant volume (Delta V = 0)

Question 24

Enthalpy (H)

Answer 24

Sum of internal energy PLUS pressure and volume (Delta H = Delta U + DeltaPV) or Delta H = a qrxn/nlimiting

Question 25

+H

Answer 25

Absorbing energy (endothermic)
Systen <—- Surroundings

Question 26

-H

Answer 26

Releasing energy (exothermic)
System —–> Surroundings

Question 27

Hess’ law

Answer 27

States that the change in enthalpy is the same whether the reaction takes place in one or a series of steps