C4 Chemical change

Question 1

What is produced when metals react with oxygen?

Answer 1

A metal oxide

Question 2

HIGHER TIER What does OIL RIG stand for?

Answer 2

Oxidation Is Loss & Reduction Is Gain (of electrons)

Question 3

What is oxidation?

Answer 3

When a substance gains oxygen (HIGHER TIER or loses electrons)

Question 4

What is reduction?

Answer 4

When a substance loses oxygen (HIGHER TIER or gains electrons)

Question 5

What type of ions do metals form?

Answer 5

Positive ions

Question 6

What type of ions do non-metals form?

Answer 6

Negative ions

Question 7

List the reactivity series

Answer 7

potassium, sodium, lithium, calcium, magnesium, aluminium, CARBON, zinc, iron, tin, lead, HYDROGEN copper, silver, gold, platinum

Question 8

What is produced when a metal reacts with an acid?

Answer 8

A salt and hydrogen gas

Question 9

What is the test for hydrogen gas?

Answer 9

A lighted splint makes a squeaky pop (when hydrogen is present)

Question 10

Name a metal that is found ‘natively’ in the ground

Answer 10

Gold / platinum

Question 11

What is the name for a rock that contains enough metal to make it economically worthwhile to extract it?

Answer 11

An ore

Question 12

What is formed when a metal carbonate and an acid react?

Answer 12

A salt + water + carbon dioxide

Question 13

What is formed when a metal reacts with water?

Answer 13

A metal hydroxide

Question 14

What is formed when magnesium reacts with nitric acid?

Answer 14

magnesium nitrate + hydrogen gas

Question 15

What is formed when lithium reacts with water

Answer 15

lithium hydroxide

Question 16

What colour does universal indicator go in a strong acid?

Answer 16

Red

Question 17

What colour does universal indicator go in a weak acid?

Answer 17

yellow or orange

Question 18

What colour does universal indicator go in a neutral solution

Answer 18

green

Question 19

What colour does universal indicator go in a weak alkali?

Answer 19

blue

Question 20

What colour does universal indicator go in a strong alkali?

Answer 20

purple

Question 21

Why can carbon be used to extract iron from its ore?

Answer 21

Iron is less reactive than carbon so carbon ‘steals’ the oxygen from the iron oxide

Question 22

Give a word equation for the extraction of iron from iron oxide by carbon

Answer 22

iron oxide + carbon -> iron + carbon dioxide

Question 23

What is formed when calcium reacts with sulfuric acid?

Answer 23

calcium sulfate + hydrogen

Question 24

What is reduced in this reaction: iron oxide + carbon -> iron + carbon dioxide

Answer 24

The iron oxide is reduced (loses oxygen)

Question 25

What is oxidised in this reaction: iron oxide + carbon -\> iron + carbon dioxide

Answer 25

The carbon is oxidised (gains oxygen)

Question 26

What is formed when magnesium reacts with hydrochloric acid?

Answer 26

magnesium chloride + hydrogen

Question 27

What is an acid?

Answer 27

Something that produces H⁺ (hydrogen) ions

Question 28

What is the formula for hydrochloric acid?

Answer 28

HCl

Question 29

What is the formula for sulfuric acid?

Answer 29

H₂SO₄

Question 30

What is the formula for nitric acid?

Answer 30

HNO₃

Question 31

What is the state symbol for a solid?

Answer 31

_(s) e.g. Mg _(s)

Question 32

What is the state symbol for a gas?

Answer 32

_(g) e.g. H_{2 (g)}

Question 33

What is the state symbol for a liquid?

Answer 33

_(l) e.g. H₂O _(l)

Question 34

What is the state symbol for a solution?

Answer 34

_(aq) e.g. H₂SO_{4 (aq)}

Question 35

What ion do aqueous solutions of alkalis produce?

Answer 35

OH^- (hydroxide) ions

Question 36

What is the pH of a neutral solution?

Answer 36

7

Question 37

What is the pH of a strong alkali?

Answer 37

Between 11 and 14

Question 38

What is the pH of a strong acid?

Answer 38

Between 1 and 3

Question 39

What is the pH of a weak alkali?

Answer 39

Between 8 and 10

Question 40

What is the pH of a weak acid?

Answer 40

Between 4 and 6

Question 41

What is the general equation for a neutralisation reaction?

Answer 41

H⁺ _(aq) + OH^- _(aq) -\> H₂O _(aq)

Question 42

What is a salt?

Answer 42

A compound formed when the hydrogen in an acid is fully or partially replaced by a metal ion (or ammonium ion)

Question 43

What are redox reactions?

Answer 43

Reactions where both reduction and oxidation take place

Question 44

(Q) In the reaction: Zn + Fe (NO3)2 --? Fe + Zn(NO3)2, which species is oxidised and which species in reduced? Why?

Answer 44

Zinc is oxidised and iron ions are reduced. This is because zinc loses electrons to form Zn 2+. Iron ions gain electrons to form Fe from Fe 2+