chemistry changes

Question 1

when metals react..

Answer 1

their atoms lose electrons to form positive metal ions

Question 2

is metals lose electrons more easily =

Answer 2

they are more reactive

Question 3

top of reactivity series =

Answer 3

lithium
sodium
potassium

Question 4

bottom of period table

Answer 4

copper, gold

Question 5

displacement reactions

Answer 5

-a more reactive metal will displace a less reactive metal

Question 6

oxidation

Answer 6

is loss of electrons

Question 7

reduction

Answer 7

is gain of electrons

Question 8

method of extraction

Answer 8

depends on how reactive it is

Question 9

pH scale

Answer 9

a measure of the acidity or alkalinity of an aqueous solution

Question 10

pH 7

Answer 10

neutral

(GREEN)💚

Question 11

pH >7

Answer 11

acidic

(RED)❤️

Question 12

pH <7

Answer 12

alkaline

(PURPLE)💜

Question 13

pH scale measured:

Answer 13

using pH probe or universal indicator

Question 14

indicators

Answer 14

dyes that change colour depending on what solutions they are in

Question 15

soluble bases=

Answer 15

alkalis

Question 16

acids are neutralised by

Answer 16

bases

Question 17

acids=

Answer 17

Contain hydrogen irons

Question 18

alkalis=

Answer 18

contain hydroxide ions

Question 19

acid + metal oxide —>

Answer 19

salt + water

Question 20

acid + metal carbonate —>

Answer 20

salt + water + carbon dioxide

Question 21

hydrochloric acid =

Answer 21

chloride salts

Question 22

nitric acid =

Answer 22

nitrate salts

Question 23

sulfuric acid =

Answer 23

sulfate salts

Question 24

strong acids

Answer 24

-completely ionised in water

hydrochloric acid, nitric acid & sulfuric acid

Question 25

weak acids

Answer 25

-partially ionised in water

ethanoic acid, citric acid & carbonic acid

Question 26

soluble salts from insoluble bases

Answer 26

can be made by reacting acids with insoluble bases

Question 27

insoluble bases

Answer 27

metal oxides, metal hydroxides & metal carbonates

Question 28

practical=

Answer 28

• copper oxide + sulfuric acid
• filter to remove any unreacted copper oxide
• evaporate using electric heater to leave behind blue crystals of the ‘salt’ copper sulfate

Question 29

electrolysis

Answer 29

using electrical current to break down compounds

Question 30

negatively charged ions move

Answer 30

to the anode

Question 31

anode

Answer 31

positive electrode

Question 32

positively charged ions move

Answer 32

to the cathode

Question 33

cathode

Answer 33

negative electrode

Question 34

negative electrode

Answer 34

• hydrogen is produced if metal is more reactive than hydrogen
• the metal is produced if the metal is less reactive than hydrogen

Question 35

positive electrode

Answer 35

• oxygen is produced unless the solution contains halide ions
• if halide ions are present, halogen is produced

Question 36

electrolysis of sodium chloride solution

Answer 36

• hydrogen is released at the negative electrode

- chlorine gas is released at the positive electrode