Energy changes: Theory

Question 1

Explain Chemical energy

Answer 1

The energy contains in any substances that can be used as fuels

Question 2

Some examples of Chemical energy usage

Answer 2

Example: Combustion reaction with fuels such as wood or coal, to produce thermal and light energy (and other usages and examples)

Question 3

Explain Energy changes

Answer 3

Transformation or Movement of energy from one form to another

Question 4

Energy change is responsible for changes in ___ and ___ reactions.

Answer 4

Matter of states, Chemical

Question 5

3 types of Heat transfer

Answer 5

Radiation, Conduction and Convection

Question 6

Exothermic reactions ___ energy as the surroudings get hotter.

Answer 6

release

Question 7

Endothermic reactions ___ energy when they get cold

Answer 7

take in / absorb in

Question 8

Most chemical reactions are ___.

Answer 8

exothermic

Question 9

Explain how Exothermic reactions work.

Answer 9

Exothermic reactions release (or) produce thermal energy to the surroundings, due to the temperature and heat.

Question 10

Explain how Endothermic reactions work.

Answer 10

Endothermic reactions absorb in (or) take in heat energy from the surroundings.

Question 11

Evaporation is an (exothermic/endothermic) reaction.

Answer 11

endothermic

Question 12

Melting is an (exothermic/endothermic) reaction.

Answer 12

endothermic

Question 13

You can identify the type of reactions by looking at the ___.

Answer 13

temperature changes

Question 14

Neutralization is an (exothermic/endothermic) reaction.

Answer 14

exothermic

Question 15

Freezing is an (exothermic/endothermic) reaction.

Answer 15

exothermic

Question 16

What are the products of combustion?

Answer 16

The substances that are created when a fuel burns

Question 16

What are the products of combustion?

Answer 16

The substances that are created when a fuel burns

Question 17

Diesel is separated from ___.

Answer 17

Crude oil

Question 18

Crude oil was found over millions of years from ___.

Answer 18

Dead animals

Question 19

Crude is a ___ source.

Answer 19

non-renewable

Question 20

Hydrogen fuel’s source

Answer 20

Methane

Question 21

What is Methane formed with?

Answer 21

Animal waste, rubbish dump

Question 22

Methane is a ___ source.

Answer 22

renewable

Question 23

Ethanol fuel is from plants, such as ___.

Answer 23

sugar cane

Question 24

Ethanol’s a ___ source.

Answer 24

renewable

Question 25

Diesel and Ethanol are in ___ state at 20*C.

Answer 25

Liquid

Question 26

Hydrogen’s state at 20*C

Answer 26

Gas

Question 27

Hydrogen can be ___ and dangerous.

Answer 27

Explosive

Question 28

…

Answer 28

Some questions can’t be answered scientifically, yet the answer can be based on the people’s opinions and beliefs.

Question 29

Equation for calculating the heat transferred to water

(not necessary)

Answer 29

H = m * c * △T

(H = heat transferred to water,
m = mass of the water,
c = heat capacity of the water,
△T = temperature change)