Chemical Changes

Question 1

what is a displacement reacrion?

Answer 1

where a more reactive metal displaces a less reactive metal from a compound

Question 2

what elements can be purely extracted from the ground

Answer 2

gold silver

Question 3

what is an ore?

Answer 3

metals combined with oxygen

Question 4

what is the removal of oxygen called?

Answer 4

reduction

Question 5

what is the gain of oxygen called?

Answer 5

oxidation

Question 6

zinc iron and copper are extracted by what proces?

Answer 6

reduction

Question 7

a metal+ oxygen makes?

Answer 7

metal oxide

Question 8

what are the 2 most reactive metals?

Answer 8

potassium, sodium

Question 9

metal + water makes?

Answer 9

metal hydroxide + hydrogen

Question 10

metal + acid makes?

Answer 10

salt + hydrogen

Question 11

how are metals more reactive than carbon extracted?

Answer 11

through electrolysis

Question 12

how is reactivity determined?

Answer 12

by how easy it is to lose its outer shell

Question 13

if something is oxidised , does it lose or gain electrons?

Answer 13

loses

Question 14

if something is reduced, does it lose or gain electrons?

Answer 14

gains

Question 15

what neutralises an acid

Answer 15

a base

Question 16

acid + base(alkali) makes?

Answer 16

salt + water

Question 17

what is an acid?

Answer 17

a substance that produces h+ ions in an aqueous solution and a ph less than 7

Question 18

what is a base?

Answer 18

a substance that has a pH of more than 7

Question 19

what is a alkali

Answer 19

produces oh- ions in aqueous solution and ph more than 7

Question 20

what is an indicator

Answer 20

a compound that changes colour

Question 21

metal hydroxide + acid makes?

Answer 21

metal salt +water

Question 22

metal oxide + acid makes?

Answer 22

metal salt + water

Question 23

metal carbonate + acid makes?

Answer 23

metal salt + water + co2

Question 24

what is a neutralisation reaction

Answer 24

when an acid reacts with a base or alkali to form water

Question 25

what kind of reaction is a redox reaction?

Answer 25

a reaction between a metal and an acid

Question 26

what is an indication of a strong acid?

Answer 26

it fully ionises in water

Question 27

if you decrease the ph of a solution by one unit, how much does the concentration increase by

Answer 27

a factor of 10

Question 28

what makes a dilute acid

Answer 28

a small number of molecules are dissolved in the solvent