chemical changes (p1)

Question 1

What is oxidation?

Answer 1

The gain of oxygen

Question 2

What is reduction?

Answer 2

The loss of oxygen

Question 3

Write a word equation for the reaction of metals with oxygen

Answer 3

metal + oxygen → metal oxide

Question 4

How do metals form ions?

Answer 4

They lose electrons to form positively charged ions

Question 5

What charge do metal ions have?

Answer 5

Positive

Question 6

Which non metals are often included in the reactivity series?

Answer 6

hydrogen and carbon

Question 7

What is the order of the reactivity series?

Answer 7

potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, copper, silver, gold

Question 8

What is an ore?

Answer 8

A compound in which a metal is naturally found

Question 9

Why are metals like gold found naturally occuring in the Earth?

Answer 9

Gold is unreactive and so doesn’t react with other elements to form compounds

Question 10

How are metals less reactive than carbon extracted from compounds?

Answer 10

Reduction with carbon

Question 11

Why can carbon be used to extract iron from iron oxide?

Answer 11

carbon is more reactive than iron

Question 12

Which element is oxidised in the reaction:
copper oxide + carbon → carbon dioxide + copper

Answer 12

carbon

Question 13

Write a word equation for the reaction of acids with metals

Answer 13

Acid + metal → salt + hydrogen

Question 14

What state is hydrogen at room temperature?

Answer 14

gas

Question 15

What is a base?

Answer 15

A substance with a pH of greater than 7. Examples include metal hydroxides and metal oxides

Question 16

What is an alkali?

Answer 16

A base that dissolves in water to release hydroxide ions and form a solution with a pH of greater than 7

Question 17

What is the formula of nitric acid?

Answer 17

HNO₃

Question 18

What is the formula of sulfuric acid?

Answer 18

H₂SO₄

Question 19

What is the formula of hydrochloric acid?

Answer 19

HCl

Question 20

Write a word equation for the reaction of an acid with an alkali

Answer 20

Acid + alkali → salt + water

Question 21

Write a word equation for the reaction of an acid with a base

Answer 21

Acid + base → salt + water

Question 22

What pH do salts have?

Answer 22

7

Question 23

Write a word equation for the reaction of a metal hydroxide with an acid

Answer 23

metal hydroxide + acid → salt + water

Question 24

Write a word equation for the reaction of a metal oxide with an acid

Answer 24

metal oxide + acid → salt + water

Question 25

What type of salts does hydrochloric acid produce?

Answer 25

chlorides

Question 26

What type of salts does sulfuric acid produce?

Answer 26

sulfates

Question 27

What type of salts does nitric acid produce?

Answer 27

nitrates

Question 28

Write a word equation for the reaction of metal carbonates with acids

Answer 28

metal carbonate + acid → salt + water + carbon dioxide

Question 29

How can you tell that a gas is produced when metal carbonates react with acids?

Answer 29

bubbles can be seen

Question 30

What is an aqueous solution?

Answer 30

The mixture formed when a substance dissolves in water

Question 31

What ion do acids release when in aqueous solutions?

Answer 31

Hydrogen ions (H⁺)

Question 32

What colour do strong acids turn universal indicator?

Answer 32

red

Question 33

What colour do weak acids turn universal indiactor?

Answer 33

yellow

Question 34

What colour do neutral substances turn universal indiactor?

Answer 34

green

Question 35

What colour do weak alkalis turn universal indicator?

Answer 35

blue

Question 36

What colour do strong alkalis turn universal indicator?

Answer 36

purple

Question 37

What ions do alkalis release when in aqueous solutions?

Answer 37

Hydroxide ions (OH ⁻)

Question 38

What does the pH scale range from?

Answer 38

0-14

Question 39

What is the pH of a neutral substance?

Answer 39

7

Question 40

What pH do acids have?

Answer 40

0-6

Question 41

What pH do alkalis have?

Answer 41

8-14

Question 42

What does soluble mean?

Answer 42

A solid that dissolves

Question 42

What is a neutralisation reaction?

Answer 42

A reaction between an acid and an alkali to produce salt and water

Question 43

Why can ionic compound conduct electricity when molten or aqueous?

Answer 43

The ions are free to move

Question 44

What is an electrolyte?

Answer 44

An ionic compound that is aqueous or molten and so able to conduct electricity

Question 45

What is a cation?

Answer 45

A positvely charged ion

Question 46

What is an anion?

Answer 46

A negatively charged ion

Question 47

What charge is the cathode?

Answer 47

Negative

Question 48

What charge is the anode?

Answer 48

positive

Question 49

What ions move towards the cathode?

Answer 49

Positively charged ions (cations)

Question 50

What ions move towards the anode?

Answer 50

Negatively charged ions (anions)

Question 51

Why do positively charged ions move towards the cathode?

Answer 51

The cathode is negatively charged and opposite charges attract

Question 52

Why do negatively charged ions move towards the anode?

Answer 52

The anode is postively charged and opposite charges attract