C4 Chemical Changes

Question 1

Metal + acid –> ?

Answer 1

Salt + hydrogen

Question 2

Metal hydroxide + acid –> ?

Answer 2

Salt + water

Question 3

Metal oxide + acid –> ?

Answer 3

Salt + water

Question 4

Metal carbonate + acid –> ?

Answer 4

Salt + water + carbon dioxide

Question 5

What is a base?

Answer 5

A substance that can neutralise an acid, with a pH greater than 7

Question 6

What is an alkali?

Answer 6

A base that dissolves in water to form a solution with a pH greater than 7

Question 7

What is an acid?

Answer 7

A substance that forms aqueous solutions with a pH less than 7

Question 8

What is the ionic equation for a neutralisation reaction?

Answer 8

OH- + H+ –> H2O

Question 9

What is the reactivity series?

Answer 9

Potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Silver
Gold

Question 10

What is an acronym for the reactivity series?

Answer 10

Please stop calling me a careless zebra. Instead, try learning how copper saves gold.

Question 11

What is a displacement reaction?

Answer 11

When a more reactive metal displaces a less reactive metal in an aqueous solution of one of its salts.

Question 12

What is an ion?

Answer 12

An atom with a charge

Question 13

What is an ionic equation?

Answer 13

One that only shows atoms and ions that change in a reaction

Question 14

Stomach acid pH

Answer 14

1

Question 15

Vinegar and lemon juice pH

Answer 15

3

Question 16

Acid rain pH

Answer 16

4

Question 17

Rain pH

Answer 17

5

Question 18

Pure water pH

Answer 18

7

Question 19

Washing-up liquid pH

Answer 19

9

Question 20

Pancreatic juice pH

Answer 20

10

Question 21

Bleach pH

Answer 21

12

Question 22

Drain cleaner pH

Answer 22

14

Question 23

What is an indicator?

Answer 23

A dye that changes colour depending on whether it’s above or below a certain pH

Question 24

What are wide range indicators? What are they useful for?

Answer 24

Indicators that contain a mixture of dyes, so they change colour gradually over a broad range of pH. They are useful when estimating pH.

Question 25

How can you measure the pH of a solution?

Answer 25

With an indicator | With a pH probe attached to a pH meter

Question 26

What is a pH probe? How accurate is it compared to an indicator?

Answer 26

An electronic device that measures the pH of a solution. They are more accurate than indicators because they output a number rather than a colour.

Question 27

Acid + base --> ? | What is this reaction called?

Answer 27

Salt + water | Neutralisation

Question 28

What is the pH of the products formed in a neutralisation reaction?

Answer 28

7 (neutral)

Question 29

What do strong acids do in water?

Answer 29

They ionise completely - all the acid particles dissociate to release H+ ions.

Question 30

What do weak acids do in water?

Answer 30

They don't fully ionise - only a small proportion of acid particles dissociate to release H+ ions.

Question 31

What do acids do in aqueous solutions?

Answer 31

They ionise

Question 32

Why are strong acids more reactive than weak ones?

Answer 32

Reactions of acids involve the H+ ions reacting with other substances. If the concentration of H+ ions is higher, the reaction will happen faster.

Question 33

What is the pH of an acid or alkali?

Answer 33

The concentration of H+ ions in the solution

Question 34

How does the concentration of H+ ions change across the pH scale?

Answer 34

For every decrease of 1 on the pH scale, it multiplies by 10

Question 35

Metal + water --> ?

Answer 35

Metal hydroxide + hydrogen

Question 36

Which metals react with water? (4)

Answer 36

Potassium, sodium, lithium, calcium

Question 37

Which metals do not react with water? (3)

Answer 37

Zinc, iron, copper

Question 38

What is an ore?

Answer 38

A compound containing enough of a metal to make it worth the cost of extracting it

Question 39

What is oxidation?

Answer 39

The gain of oxygen and the loss of electrons

Question 40

What is reduction?

Answer 40

The loss of oxygen and the gain of electrons

Question 41

What does OIL RIG stand for?

Answer 41

Oxidation Is Loss, Reduction Is Gain (of electrons)

Question 42

Which metals can be extracted by reduction with carbon? (general case and 3 examples)

Answer 42

Those which are below carbon in the reactivity series. | Zinc, iron, copper

Question 43

What does PANIC stand for?

Answer 43

Positive Anode, Negative Is Cathode

Question 44

Which reactants are reduced and oxidised in a displacement reaction?

Answer 44

The metal ion is reduced, the metal atom is oxidised

Question 45

Which ions are attracted to which electrodes in electrolysis?

Answer 45

The positive metal ions go to the negative cathode, the negative non-metal ions go to the positive anode.