acids and alkalis

Question 1

acid

Answer 1

a substance that has a pH lower than 7

Question 2

corrosive

Answer 2

a substance which reacts with materials and makes them dissolve

Question 3

irritant

Answer 3

something that reddens the skin

Question 4

hydrogen

Answer 4

the atom present in all acids

Question 5

soapy

Answer 5

the effect produced when an alkali is added to water

Question 6

hydroxide

Answer 6

the particle present in alkalis

Question 7

indicator

Answer 7

a dye that can change colour when placed in environments with different pH values

Question 8

litmus

Answer 8

an indicator which tells us if something is an acid or an alkali

Question 9

neutral

Answer 9

when a substance is neither acidic nor alkaline and has pH of 7

Question 10

strong acid/alkali

Answer 10

contains a lot of hydrogen ions/particles (acid) or a lot of hydroxide ions/particles (alkali)

Question 11

weak acid/alakali

Answer 11

contains only a few hydrogen particles/ions (acid) or a few hydroxide particles/ions (alkali)

Question 12

universal indicator

Answer 12

a mixture of dyes which create a range of colour depending on the strength of acidity or alkalinity being tested

Question 13

pH number

Answer 13

the scale from 1-14 which shows acidity or alkalinity

Question 14

neutralisation

Answer 14

when an acid and alkali combine resulting in products with pH of 7

Question 15

titration

Answer 15

a laboratory method allowing accurate volumes of liquids to be measured

Question 16

water

Answer 16

a molecule of water contains 2 hydrogen atoms and 1 oxygen atom

Question 17

salt

Answer 17

a substance formed when an acid reacts with a base

Question 18

equation

Answer 18

a way of summarising a chemical reaction with the reactants on the left of the arrow and the products on the right

Question 19

base

Answer 19

something which neutralises an acid

Question 20

chemical reaction

Answer 20

a process in which one or more substances are changed into others by their atoms being rearranged

Question 21

reactivity

Answer 21

how reactive a substance is

Question 22

carbonate

Answer 22

a type of compound containing carbon and oxygen

Question 23

carbon dioxide

Answer 23

the gas in the air used by plants to make food . it is produced during respiration by burning fossil fuels or by acids reacting with metal carbonates

Question 24

limewater

Answer 24

a solution used to test for the presence of carbon dioxide

Question 25

indigestion

Answer 25

disruption of the digestion process often resulting in too much acid being produced

Question 26

heartburn

Answer 26

when acid from the stomach irritates the upper digestive tract

Question 27

antacid

Answer 27

a substance that neutralises stomach acid

Question 28

fertiliser

Answer 28

a chemical put on soil to increase fertility and allow better growth of crop plants

Question 29

misconception

Answer 29

a common idea that people share that is inaccurate

Question 30

fuel

Answer 30

a material that is burned to release its energy

Question 31

combustion

Answer 31

the process of burning

Question 32

fire triangle

Answer 32

a model to show the three things needed for a fire - heat, fuel and oxygen

Question 33

exothermic

Answer 33

a chemical reaction in which heat energy is given out

Question 34

energy

Answer 34

something has energy if it has the ability to make something happen when the energy is transferred

Question 35

alcohol

Answer 35

a liquid chemical such as ethanol which can be used as a biofuel

Question 36

sulfur dioxide

Answer 36

is produced when sulfur is oxidised during the combustion of some fossil fuels and is one of the main gases that produces acid rain

Question 37

acid rain

Answer 37

rainwater that is made acidic by pollutant gases e.g. sulfur dioxide