C4 Chemical Changes

Question 1

What is the use of the reactivity series

Answer 1

Make predictions about the reactions of metals

Question 2

What 2 non metals are included in the reactivity series and which is more reactive than the other

Answer 2

Carbon (more reactive)
Hydrogen (less reactive)

Question 3

What are the 4 state symbols

Answer 3

(s) - solid
(l) - liquid
(g) - gas
(aq) - aqueous ( in sol. )

Question 4

What does reacting a metal with oxygen create

Answer 4

(Metal) oxide

Question 5

What is created when a metal is reacted with water

Answer 5

(Metal) Hydroxide

Question 6

What is created when a metal is reacted with sulphuric acid

Answer 6

(Metal) sulphate

Question 7

What is created when a metal is reacted with hydrochloric acid

Answer 7

(Metal) chloride

Question 8

What is created when a metal is reacted with nitric acid

Answer 8

(Metal) nitrate

Question 9

What are salts

Answer 9

A metal and non-metal chemically bonded together

Question 10

What type of bonding is in salts

Answer 10

Ionic ( strong electrostatic force )

Question 11

What is a displacement reaction

Answer 11

When a more reactive metal takes the place of a less reactive metal
(E.g. copper nitrate + potassium ——> potassium nitrate + copper)

Question 12

What is a reduction reaction

Answer 12

When an atom gains an electron (Reduction Is Gain)

Question 13

What is an oxidisation reaction

Answer 13

When an atom loses electrons (Oxidisation Is Loss)

Question 14

What are native metals

Answer 14

Pure metals that are found in the ground

Question 15

What metals are usually found native and why

Answer 15

Metals less reactive than hydrogen (e.g. platinum, gold, silver, copper)
They are so inert that they don’t react with there surroundings

Question 16

What is an ore

Answer 16

A rock with a high enough concentration of metal atoms to make it viable enough for commercial use

Question 17

What metals are found as ores

Answer 17

Anything more reactive than copper

Question 18

Why is carbon used to reduce metals less reactive than it

Answer 18

Easy to produce/cheap

Question 19

What element do all acids contain

Answer 19

Hydrogen (H)

Question 20

What compound do all alkalis contain

Answer 20

Hydroxide (OH^-)

Question 21

What are the products when a metal is used to create a salt

Answer 21

Salt + hydrogen

Question 22

What is a base

Answer 22

Ionic compound that can neutralise acids

Question 23

What is the difference between bases and alkalis

Answer 23

Alkalis are soluble bases

Question 24

What products are created when bases are reacted with an acid

Answer 24

Salt + water

Question 25

What is the reaction of an acid and a base/alkali called

Answer 25

A neutralisation reaction

Question 26

What is a neutralisation reaction

Answer 26

Hydrogen and hydroxide ions reacting to create water ( neutral) so the concentration of hydrogen/hydroxide ions decreases

Question 27

What products are created when alkalis are reacted with an acid

Answer 27

Salt+water

Question 28

What products are created when carbonates are reacted with an acid

Answer 28

Salt + carbon dioxide

Question 29

What are the 4 general word equation that are used to make salts

Answer 29

Acid + Metal ——> salt + hydrogen Acid + Base ——> salt + water Acid + Alkali ——> salt + water Acid + carbonate——> salt + carbon dioxide

Question 30

What does pH stand for

Answer 30

Potential of hydrogen

Question 31

What is the correlation between pH and concentration of H+ ions

Answer 31

1.0 * 10^-(pH value)

Question 32

What colour is a neutral in universal indicator

Answer 32

Green

Question 33

What colour is an acid in universal indicator

Answer 33

Red

Question 34

What colour is an alkali in universal indicator

Answer 34

Purple/indigo

Question 35

What are the 4 components of an electrolysis circuit

Answer 35

Power supply Electrolyte Positive electrode (anode) Negative electrode (cathode)

Question 36

What is the name of the positive electrode in electrolysis

Answer 36

The anode

Question 37

What is the name of the negative electrode in electrolysis

Answer 37

The cathode

Question 38

Why does the electrolyte have to be an ionic compound

Answer 38

So the charged particles (ions) can move to the electrode

Question 39

Why do electrolytes have to be molten or aqueous

Answer 39

So the ions can flow

Question 40

Where do metal ions flow to in electrolysis and why

Answer 40

The cathode (negative electrode) as opposite charges attract each other

Question 41

Where do non-metal ions flow to in electrolysis and why

Answer 41

The anode (positive electrode) as opposite charges attract each other

Question 42

What is the half equation at the cathode

Answer 42

Metal ion + e- —> metal (E.g. Pb^+2+ 2e- —> Pb)

Question 43

What is the half equation at the anode

Answer 43

Non-metal ion —> Non-metal + e- (E.g. 2Br^- —> Br + e-)

Question 44

What is the name of aluminium ore

Answer 44

Bauxite

Question 45

What is aluminium oxide dissolved it to lower its melting point

Answer 45

Cryolite(Na3AlF6) - brings melting temp down to 1000-900 degrees Celsius

Question 46

What is the aqueous solution used in the electrolysis RP

Answer 46

Copper(II) chloride

Question 47

What is the method of separating copper and chlorine (Electrolysis RP)

Answer 47

1. Pour 50cm^3 of copper(II) chloride into a beaker then place a Petri dish with two holes over the top 2. Insert 2 graphite rods into each hole(they must not touch) 3. Attach graphite rods to crocodile leads to the rods and connect them to a low-voltage power supply 4. Set power pack to 4v and switch on 5. The cathode should be coated with copper and the anode should be gas bubbles of chlorine

Question 48

Why is graphite used as the electrodes

Answer 48

They are inert