God Knows

Question 1

Thermochemistry

Answer 1

The study of the transfer of energy as heat during chemical reactions and physical changes

Question 2

First Law of Thermodynamics

Answer 2

The total energy in the universe is constant and can neither be created nor destroyed, only tansformed

Question 3

Energy

Answer 3

The capacity to do work

Question 4

Forms of Energy

Answer 4

Potential
Kinetic
Thermal

Question 5

Potential Energy

Answer 5

Stored energy or the energy of position
The energy stored within the bonds between atoms

Question 6

Kinetic Energy

Answer 6

The energy of motion

Question 7

Thermal Energy

Answer 7

Heat

Question 8

To Break Bonds of Reactants in a Reaction

Answer 8

It takes energy
Absorbed

Question 9

Bonds of Reactants Broken

Answer 9

Potential energy transforms to kinetic
Atoms are rearranged in motion
New bonds form as products are formed which releases energy as thermal energy

Question 10

When a Chemical Reaction Takes Place

Answer 10

Bonds of the reactants are broken, taking energy
If the energy is not enough to break the bonds the reaction will not occur
Atoms are rearranged
New bonds are formed and the products release energy

Question 11

Breaking VS Forming Bonds

Answer 11

Requires energy
Releases energy

Question 12

Calorimetry

Answer 12

The measurement of heat flow into or out of a system during a chemical reaction or physical change

Question 13

Heat Released By System

Answer 13

Equals heat absorbed by surroundings
Vice versa

Question 14

Calorimeter

Answer 14

Instrument in calorimetry used to measure heat energy lost or gained by the system and its surroundings
Insulated device to capture all heat either absorebed or released

Question 15

Water in Calorimeter

Answer 15

Used to surround the reaction as it is stable and has a high specific heat

Question 16

Amount of Heat Absorbed or Released

Answer 16

Can be measured by the change in themperature of a known quantity of water

Question 17

Change in Temperature Depends On

Answer 17

Amount of heat energy added
Mass of the substance
Composition of the substance

Question 18

Specific Heat

Answer 18

The amount of energy required to raise the temperature of one gram of the substance by one degree Celsius

Question 19

Specific Heat Depends On

Answer 19

Physical properties
Each substance has its own unique specific heat
Varies on state of material

Question 20

Water Specific Heat

Answer 20

Liquid 4.184
Gas 1.87
Solid
2.06

Question 21

C=q/m*∆T

Answer 21

C=specific heat at given pressure
q=heat energy lost or gained
m=mass
∆T=change in temperature (Tf-Ti)

Question 22

<1J/gºC

Answer 22

Metal

Question 23

Use

Answer 23

Celsius

Question 24

Exothermic

Answer 24

-q
Products have less potential energy than reactants
Reactants –> products + energy
Energy of reactants = energy of products + energy released
Energy release
Copy diagrams

Question 25

Endothermic

Answer 25

+q Products have more potential energy than reactants Reactants + energy --> products Energy of reactants + energy absorbed = energy of products Absorb energy Copy diagrams

Question 26

∆H

Answer 26

Change in energy

Question 27

Activation Energy

Answer 27

Minimum amount of energy required to overcome the bond energies of the reactants/break bonds

Question 28

Enthalpy

Answer 28

(H) Heat of a substance at constant pressure No direct way to measure this so we measure change in enthalpy ∆H

Question 29

∆H

Answer 29

The amount of heat that is absorbed or released by the system under conditions of constant pressure Equal to the difference between the enthalpies of the products and the reactants

Question 30

Heat of Reaction

Answer 30

The amount of heat that is absorbed or released during a chemical reaction

Question 30

∆H=

Answer 30

Hproducts - Hreactants

Question 31

Endothermic Energy Absorbed

Answer 31

Stored energy of products is greater than the stored energy of reactants so enthalpy change is positive

Question 32

Exothermic Energy Released

Answer 32

Stored energy of products is less than stored energy of reactants so enthalpy change is negative

Question 33

Thermochemical Equation

Answer 33

The amount of themal energy lost or gained during a reaction shown as part of the chemical equation

Question 34

Released

Answer 34

Means heat is lowering

Question 35

Law of Conservation of Energy

Answer 35

All the energy water gains came from energy given off from the food J of heat gained = J of heat lost

Question 36

Heat

Answer 36

The energy associated with the random motion of particles

Question 37

Unit for Heat Energy

Answer 37

Joules

Question 38

Heat Capacity

Answer 38

The energy required to raise the temperature of a one gram sample of a substance one degree Celsius