Unit Seven B

Question 1

Energy

Answer 1

The ability to do work OR produce heat

Question 2

Law of conservation of energy

Answer 2

Energy cannot be created or destroyed, only changed

Question 3

Chemical potential energy

Answer 3

Energy that is stored within chemical bonds, ex. fossil fuels

Question 4

Heat

Answer 4

Flows from hotter objects to colder objects until equal temperature is reached

Question 5

Units of heat energy: calorie

Answer 5

Amount of heat required to raise the temperature of one gram of water by one degree Celsius
One dietary calorie is one thousand other calories

Question 6

Units of heat energy: joule

Answer 6

SI unit of heat and energy, the amount of heat required to raise the temperature of one gram of water by 0.239 degrees Celsius

Question 7

Conversion factors

Answer 7

One calorie = 4.184 joules

One joule = 0.239 calories

Question 8

Thermochemistry

Answer 8

The study of heat changes in chemical reactions and physical changes

Question 9

System

Answer 9

Specific part of the universe that contains the reaction or process you wish to study

Question 10

Surroundings

Answer 10

Everything other than the system

Question 11

Exothermic

Answer 11

Heat leaves the system (gives off heat)

Heat change

Question 12

Endothermic

Answer 12

Heat enters the system (absorbs heat)
System gains heat
Heat change is > 0
Ex, energy and solid water to liquid water

Question 13

Activation energy

Answer 13

Ea, minimum amount of energy needed for the reaction to occur

Question 14

How to find Exothermic or endothermic

Answer 14

Products - reactants
- = Exothermic
+ = endothermic
STUDY P5

Question 15

Enthalpy (H)

Answer 15

The amount of heat within a system

The change in enthalpy can be found by taking the difference in energy from the products vs reactants

Question 16

Specific heat capacity

Answer 16

The amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius

Question 17

Specific heat equation

Answer 17

q = mCΔT

Question 18

Calorimetry

Answer 18

The accurate and precise measurement of heat change for Chem reactions and physical processes
Measurements are made using an insulated container called a calorimeter
Assumed that heat lost = heat gained

Question 19

How to find when two objects

Answer 19

mCΔT = mCΔT

Question 20

Enthalpy

Answer 20

The energy required for a change of state

Question 21

Enthalpy of vaporization

Answer 21

Energy needed to vaporize one gram of substance when substance is already at its boiling point

Question 22

Enthalpy of fusion

Answer 22

Energy required to melt something when it is already at its melting point

Question 23

Internal energy

Answer 23

The total a,punt of all the potential and kinetic energy that a system has

Question 24

Equation for internal energy (U)

Answer 24

KE + PE = U

Question 25

First law of thermodynamics

Answer 25

The change in internal energy of a system equals the sum of the heat and the work. If a system is heated it gains internal energy but if the system loses heat it decreases in internal energy. If a system does work it loses internal energy but if work is done on the system it gains internal energy.

Question 26

Enthalpy (again I guess lol)

Answer 26

The heat energy involved in a chemical reaction.

Question 27

Change in enthalpy

Answer 27

Change in heat energy for a reaction, units of kJ, symbol is change in H

Question 28

Enthalpy of formation

Answer 28

Whenever one substance is made from elements in their standard states, the accompanying enthalpy change is called the enthalpy of formation

Question 29

Spontaneous

Answer 29

If a process occurs naturally, all by itself without outside help or energy being supplied to it

Question 30

Entropy

Answer 30

Change in amount of disorder or randomness is called change in entropy

Question 31

Delta S is positive

Delta S is negative

Answer 31

Disorder increases

Disorder decreases