Energy Transfer (McLean & Brett)

Question 1

Exothermic reactions

Answer 1

When energy gets transferred from the reacting chemical to the surroundings and the temperature goes up

Question 2

Endothermic reactions

Answer 2

when energy is transferred from the surroundings to the reacting chemicals and the temperature goes down

Question 3

Are reactions most exothermic or endothermic?

Answer 3

Exothermic

Question 4

fuel

Answer 4

a material that can be burnt to produce heat or power

Question 5

Hydrocarbon

Answer 5

Hydrogen + carbon, found in fossil fuels burns to form carbon dioxide and hydrogen

Question 6

Complete combustion

Answer 6

when there is a good supply of oxygen

Question 7

Complete combustion triangle

Answer 7

heat + fuel + oxygen

Question 8

Complete combustion equation

Answer 8

Fuel + Oxygen –> Water + Carbon dioxide + Carbon monoxide

Question 9

Incomplete combustion

Answer 9

when supply of oxygen or air is poor

Question 10

Incomplete combustion equation

Answer 10

Fuel + Oxygen –> Carbon monoxide + Carbon + Water

Question 11

How chemical energy changes in exothermic reactions

Answer 11

chemical energy becomes heat energy

Question 12

∆H

Answer 12

Change in energy

Question 13

Types of energy

Answer 13

Chemical energy, kinetic energy, nuclear energy, light energy, sound energy, gravitational potential energy

Question 14

Sublimation

Answer 14

solid to gas

Question 15

Deposition

Answer 15

Gas to solid

Question 16

Example of something that sublimates

Answer 16

Iodine

Question 17

Exothermic changes of state

Answer 17

Gas –> Liquid –> Solid

Question 18

Endothermic changes of state

Answer 18

Solid –> Liquid –> Gas

Question 19

Mint plant experiment

Answer 19

Joseph put a candle and a mint plant in a jar and one with just a candle, he realized that the candle with the plant lasted longer, and then put a mouse in and the mouse lived in the mint plant one and died int he jar without a plant, showing how oxygen is released in photosynthesis, proved photosynthesis is endothermic and respiration is exothermic

Question 20

Jan ingenhousz experiment

Answer 20

Proved light is needed in photosynthesis, by putting leaves and plants in a transparent container and put them under water, he put one next to sunlight and one in the dark, bubbles were produced in the one next to the sunlight

Question 21

Good conductors

Answer 21

Metals because they are dense and have free moving electrons

Question 22

Conduction

Answer 22

Conduction is when thermal energy is transferred via vibrations, the distance of a conductor over time

Question 23

Convection

Answer 23

The movement of fluid when the denser/colder one sinks and the less dense/hotter one rises

Question 24

Radiation

Answer 24

emission of energy as electromagnetic waves or as subatomic particles

Question 25

Absorber

Answer 25

Object that has the ability to take in energy

Question 26

Emitter

Answer 26

Object that has the ability to give out energy

Question 27

Reflector

Answer 27

Object that has the ability to let energy bounce off its surface

Question 28

Rough objects

Answer 28

Good absorbers, good emitters, poor reflectors

Question 29

Smooth objects

Answer 29

Poor absorbers, poor/ok emitters, good reflectors

Question 30

Dull objects

Answer 30

Good absorbers, good emitters, poor reflectors

Question 31

Shiny Objects

Answer 31

Poor absorbers, poor emitters, good reflectors