Y11 Mock Chemical Changes

Question 1

definition of reduction

Answer 1

gain of electrons/ loss of oxygen

Question 2

definition of oxidation

Answer 2

loss of electrons/gain of oxygen

Question 3

reactivity series

Answer 3

potassium
sodium
calcium
magnesium
aluminium
carbon
zinc
iron
tin
lead
hydrogen
copper
silver
gold
platinum

Question 4

what can a more reactive metal do (reactivity series)

Answer 4

displace a less reactive metal from a compound

Question 5

metal and water word equation

Answer 5

metal + water —> metal hydroxide + hydrogen

Question 6

what does a more reactive metal in the reactivity series mean (terms of ions)

Answer 6

faster reaction so can form positive ions faster

Question 7

steps for writing an ionic equation

Answer 7

rewrite the equation showing the separate ions present in each substance
remove any spectator ions(ions that don’t change state or charge)
rewrite the equation without spectator ions

Question 8

half equation for oxidation

Answer 8

electrons always on the right

Question 9

half equation for reduction

Answer 9

electrons always on the left

Question 10

what do acids and metals produce

Answer 10

salts + hydrogen

Question 11

what is the metal hydroxide always

Answer 11

alkaline

Question 12

acid and alkali word equation

Answer 12

alkali + acid –> salt +water

Question 13

what kind of reaction is acids with alkali

Answer 13

neutralisation reaxton

Question 14

acids and bases word equation

Answer 14

base + acid –> salt + water

Question 15

what kind of reaction is acids and bases

Answer 15

neutralisation reaction

Question 16

naming salts steps

Answer 16

first part - metal in the metal carbonate/oxide/hydroxide
second part - acid used to make it

Question 17

what are acids neutralised by

Answer 17

alkalis and bases to produce salts and water

Question 18

what is a strong acid

Answer 18

an acid completely ionised in aqueous solution

Question 19

what is a weak acid

Answer 19

an acid partially ionised in aqueous solution

Question 20

what is a dilute acid

Answer 20

acid molecules mixed with a large amount of water
low concentration of H+ ions

Question 21

what is concentration in terms of acids

Answer 21

amount of H+ ions present in an acid affected by number of water molecules

Question 22

equation to find H+ ion concentration

Answer 22

[H+] = 10 ^ -PH

Question 23

titration calculation steps

Answer 23

write what you know from the question (known is where there’s a value for concentration and volume)
work out number of moles for known using moles = concentration x volume / 1000
work out ratio using equation for moles of unknown
workout unknown concentration = moles x1000/ volume
convert mol/dm3 to g/dm3 by using concentration in g/dm3 = concentration in mol/dm3 x mr of substance

Question 24

steps of electrolysis of an aqueous solution

Answer 24

4 ions in the beaker
ions move to the electrodes
ions are discharged
half equations of what happens at each electrode
write what is left in the container

Question 25

rules for the anode in electrolysis of a solution

Answer 25

if -ions are halogens , the halogen is made
if -ions are not halogens , oxygen is produced

Question 26

rules for the cathode in electrolysis of a solution

Answer 26

if +ions are more reactive than hydrogen, hydrogen is produced
if +ions are less reactive than hydrogen, the metal is produced