Unit 3: Energy changes/ Rates Reaction

Question 1

Thermochemistry

Answer 1

Study of energy changes that accompany physical/chemical changes in matter

Question 2

Energy

Answer 2

The ability to do work; SI unit Joules

Question 3

Work

Answer 3

Amount of energy transferred by a force over a distance; SI unit joules

Question 4

Potential energy

Answer 4

Energy of a body or system due to its position or composition

Question 5

Kinetic energy

Answer 5

Energy of an object due to its motion

Question 6

Thermal energy

Answer 6

Total quantity of kinetic/pot. Energy in a substance

Question 7

Heat

Answer 7

Transfer of thermal energy from a warm object to a cooler object

Question 8

Temperature

Answer 8

Measure of the average kinetic energy of entities in a substance

Question 9

Chemical system

Answer 9

Group of reactants and products being studied

Question 10

Open system

Answer 10

System in which both matter and energy are free to enter and leave

Question 11

Closed system

Answer 11

System in which matter/energy can enter and leave the system but mattercannot

Question 12

Isolated system

Answer 12

An ideal system in which neither matter nor energy can move in or out (impossible on Earth)

Question 13

Exothermic

Answer 13

Releasing energy to the surroundings
Reactants have higher pot energy than products

Question 14

Endothermic

Answer 14

absorbing energy from the surroundings
Reactants have lover potential energy than products

Question 15

Nuclear fission

Answer 15

Process of using a neutron to split a nucleus of high atomic mass in 2 nuclei w/ smaller masses

Question 16

Nuclear fusion

Answer 16

The process of combining 2+ nuclei of low atomic mass to form a heavier more stable nucleus

Question 17

Specific heat capacity

Answer 17

Quantity of thermal energy required to raise temp of 1g of a substance by 1C;
Unit J/ g C

Question 18

Calorimetry

Answer 18

Experimental process of measuring the thermal energy change in a chemical or physical change

Question 19

Calorimeter

Answer 19

Device used to measure thermal energy changes; well insulated reaction bc hammer

Question 20

Enthalpy (H)

Answer 20

Total amount of thermal energy in a substance ( cannot be measured)

Question 21

Enthalpy change (delta H)

Answer 21

Energy released to or absorbed from surroundings during a chemical or physical change

Pressure must remain constant

Question 22

Molar Enthalpy (delta H r)

Answer 22

Energy change that occurs when 1 mole of a substance undergoes a change

Question 23

Standard enthalpies of formation

Answer 23

The change in Enthalpy that occurs when 1 mol of a compound is formed from its elements with all substance in their standard states