C4:Chemical changes

Question 1

what is reduction in terms of oxygen

Answer 1

loss of oxygen

Question 2

what is oxidation in terms of oxygen

Answer 2

gain og oxygen

Question 3

name the most reactive substance in the reactivity series

Answer 3

potassium

Question 4

what comes after p…

Answer 4

sodium

Question 5

what comes after so…

Answer 5

lithium

Question 6

what comes after lith…

Answer 6

calcium

Question 7

what comes after cal….

Answer 7

magnesium

Question 8

what comes after mag…

Answer 8

zinc

Question 9

what comes after zi…

Answer 9

iron

Question 10

what is the least reactive metal in the reactivity series

Answer 10

copper

Question 11

what are the non metals in the reactivity seris

Answer 11

hydrogen and carbon

Question 12

what happens when you react a metal and an acid

Answer 12

salt + hudrogen

Question 13

from potassium to calcium how do the substances react with water and acids

Answer 13

very violent but gradually goes down

Question 14

from magnesium onwards how do the substances react with water and acids

Answer 14

produce bubbles but produce fewer bubbles as you go down

Question 15

what happens when you react water and metals

Answer 15

metal hydroxides + hydrogen

Question 16

what happens in a displacement reaction

Answer 16

more reactive matal displaces less reactive metal
e.g. mg +FeSO4 –> MgSO4 +Fe

Question 17

how can we extract pure metals from a compound using carbon

Answer 17

if a compound is less reactive than carbon it will displace the compound and make carbon dioxide

Question 18

how would you extract metals from potassium to magnesium

Answer 18

electrolysis

Question 19

what is a redox reaction

Answer 19

a reaction that has both reduction and oxidation

Question 20

what is a rule in an ionic equation

Answer 20

only show particles that take place in the reaction
e.g. Ca +Fe^2+SO4^-4 —> Ca^2+SO4^-4 +Fe
Ca +Fe^2+ —> Ca^2+ + Fe

Question 21

what is the chemical formula for nitric acid

Answer 21

HNO₃

Question 22

what happens when you react metal oxide or metal hydroxide with an acid

Answer 22

salt + water

Question 22

what is the chemical formula for

Answer 22

H₂SO₄

Question 22

Required practical: how do you make soluble salts using a insoluble base

Answer 22

step 1: put a dilute acid into a beaker and heat it with a Bunsen burner
step 2:add insoluble base a little at a time as you add more some of the base will stop disappearing
step 3 : filter all excess base using filter paper and filter funnel
step 4 : get the soluble salt and heat it up using a electric heater
step 5 :once some of the water is evaporated and crystals start to form stop heating and leave it to cool
step 5 : filter it out using filter paper and a funnel
step 6 : dry the crystals

Question 23

Acid + metal carbonates

Answer 23

salt + water + carbon dioxide

Question 24

how do you make a soluble salt

Answer 24

Acid vs insoluble base

Question 25

what do acids produce in an aqueous solution

Answer 25

hydroxide ions (H+)

Question 26

what do aqueous solutions of alkaline contain

Answer 26

hydroxide ions (OH-)

Question 27

what happens in neutralisation reactions between alkalines and acids

Answer 27

Hydrgen ions react with hydroxide ions to produce water
e.g H+ + OH- —> H2O

Question 28

what is a base

Answer 28

any substance with a ph greater than 7

Question 29

what is the chemical formula for sodium hydroxide (base)

Answer 29

NaOH

Question 30

what is the chemical formula for calcium carbonate (base)

Answer 30

CaCo3

Question 31

what will happen to the ph of a strong acid if it has the same concentration as a weak acid

Answer 31

lower ph

Question 32

what will happen to concetration if you change the ph by 1

Answer 32

change by 10x