Nature's Chemistry

Question 1

Name the 3 fossil fuels

Answer 1

gas,oil,coal

Question 2

Why are fossil fuels called ‘fossil fuels’

Answer 2

they formed millions of years ago from dead animals and plants

Question 3

What is crude oil?

Answer 3

A thick black liquid containing a mixture of hydrocarbons

Question 4

What is crude oil used for?

Answer 4

fuels, plastics, medicines

Question 5

What is a fraction?

Answer 5

A group of hydrocarbons with similar boiling points

Question 6

What elements are present in hydrocarbons?

Answer 6

Hydrogen and carbon

Question 7

Describe what saturated means when referring to hydrocarbons

Answer 7

single carbon-carbon bonds

Question 8

Describe what unsaturated means when referring to hydrocarbon

Answer 8

double carbon-carbon bonds

Question 9

What is a addition reaction?

Answer 9

When a molecule adds into a double bond to make one molecule

Question 10

Describe the industrial process of cracking hydrocarbons

Answer 10

When large chain hydrocarbons are broken into smaller, more useful alkanes and alkenes

Question 11

State the types of hydrocarbons formed in a cracking reaction

Answer 11

alkanes and alkenes

Question 12

Give the definition of a fuel

Answer 12

A substance that burns to produce energy

Question 13

Give the definition of combustion

Answer 13

Burning in oxygen to produce heat

Question 14

Name the type of compounds that mainly make up fossil fuels

Answer 14

Hydrocarbons

Question 15

What happens to lime water when carbon dioxide is present

Answer 15

It goes cloudy

Question 16

Describe incomplete combustion

Answer 16

When there is not enough oxygen for the substance to burn completely.

Question 17

Name the products of incomplete combustion of fossil fuels

Answer 17

Carbon, Carbon monoxide in addition to CO2 and H2O

Question 18

What does the fire triangle contain.

Answer 18

Fuel, heat, oxygen

Question 19

What are the reactants in photosynthesis?

Answer 19

carbon dioxide, water, light energy

Question 20

What are the products in photosynthesis?

Answer 20

oxygen glucose

Question 21

Where does energy come from in photosynthesis?

Answer 21

sunlight

Question 22

Write a word equation for photosynthesis

Answer 22

carbon dioxide+water+light energy->glucose+oxygen

Question 23

write a chemical equation for photosynthesis

Answer 23

CO2 + H2O + light energy->C6 H12 O6+O2

Question 24

why are fertilisers added to soils?

Answer 24

increase crop growth

adds nutrients to the soil

Question 25

State the hydrogen : oxygen ratio for carbohydrates

Answer 25

2:1

Question 26

What is the test for starch?

Answer 26

Iodine

Question 27

what is the test for glucose?

Answer 27

benedicts solution

Question 28

compare the size of glucose molecules with starch molecules

Answer 28

starch molecules are bigger than glucose molecules

Question 29

describe what happens to starch during digestion

Answer 29

the starch is broken down into smaller molecules

Question 30

describe what the body does with the glucose after digestion

Answer 30

it enters the bloodstream used for respiration

Question 31

describe the process of fermentation

Answer 31

fermentation is the reaction that converts glucose in plants into the alcohol ethanol

Question 32

describe the function of yeast in fermentation

Answer 32

yeast is a living organism, it eats the glucose and converts it into CO2 and alcohol

Question 33

what colour does cobalt chloride paper turn if water is present

Answer 33

blue - pink