L1-7

Question 1

Metal+oxide

Answer 1

Metal oxide

Question 2

Metal+water

Answer 2

Metal hydroxide+hydrogen

Question 3

Metal+steam

Answer 3

Metal oxide+hydrogen

Question 4

Metal+dilute acid

Answer 4

Salt+hydrogen

Question 5

Oxidation

Answer 5

Loss of electrons

Question 6

Reduction

Answer 6

Gain of electrons

Question 7

Electrolysis

Answer 7

Breakdown of an ionic compound, molten or in aqueous solution by the passage of electricity

Question 8

Only works for ionic compounds when they are either… b/c…

Answer 8

Molten/dissolved in water b/c can only conduct electricity in these states b/c ions need to be able to move

Question 9

Process of electrolysis

Answer 9

Electric current causes a chemical reaction that breaks down the ionic compound. The ionic compound decomposes

Question 10

Electrode

Answer 10

Rods that carry electric current to and from electrolyte.
Normally made from inert substance e.g graphite or platnium

Question 11

An ode

Answer 11

Positive electrode-> t/f attract anions

Question 12

Cathode

Answer 12

Negative electrode t/f attract cations

Question 13

Electrolyte

Answer 13

Solution (aq) or (l)

Question 14

Oxidation always happens at

Answer 14

Anode

Question 15

Reduction always happens at

Answer 15

Cathode

Question 16

Purifying copper by electrolysis

Answer 16

Electricity is passed through solutions containing copper compounds e.g copper sulfate
Anode is made from impure copper and cathode is made from pure copper

Question 17

Extraction of metals

Answer 17

A few metals are so unreactive that they occur in pure state e.g copper, silver and gold
Most metals= too reactive to exist on own and exist in ores

Question 18

Metals less reactive than carbon

Answer 18

Can be extracted from ores by reduction with carbon using a displacement reaction
E.g reduce copper oxide to copper by heating with carbon

Question 19

Why do the anodes need replacing regularly in extraction of aluminium

Answer 19

B/c both electrodes are carbon, then as oxygen gas is produced at anode, electrodes begin to burn away

Question 20

Primary standard

Answer 20

Solution with accurately known concentration

Prepared by dissolving a measured amount of solute in a known volume of solvent

Question 21

Redox titration

Answer 21

Using a redox reaction (rather than a neutralisation reaction) to determine the concentration of a solution

Question 22

In redox, not using ph indicator b/c

Answer 22

Titration will do self-indication

Question 23

Potassium manganate solution has a

Answer 23

Distinctive purple colour

Question 24

Diatomic elements

Answer 24

Hydorgen, iodine, nitrogen, chlorine, bromine, oxygen, fluroine

Question 25

Haber process describe

Answer 25

Name given to the industrial production of ammonia (NH3) which can be used for fertilisation, dyes or explosives Nitrogen and hydrogen are reacted together using an iron catalyst to produce ammonia

Question 26

Haber process equation reaction

Answer 26

N2 (g) + 3 H2 (g) -><- 2NH3 (g)

Question 27

Problem with temp too low

Answer 27

Rate of reaction = too slow that take too long to make ammonia

Question 28

Problem with increasing pressure to increase yield

Answer 28

If pressure= too high, equip. Needed to safely contain reaction and becomes expensive

Question 29

Compromised conditions

Answer 29

Temp of 450 degrees keeps rate of reaction high in combo with use of hot iron catalyst-> good yield of ammonia produced

Question 30

If the reaction for hp favour production of ammonia, then

Answer 30

Forward reaction is favoured and equilibrium has shifted to right-> increases yield of ammonia

Question 31

If reaction of hp favour production of h2 and n2 gas, then

Answer 31

Reverse reaction is favoured and equilibrium has shifted to left Increases yield of n2 and h2

Question 32

Forward reaction producing ammonia=

Answer 32

Exothermic reaction b/c releases energy in form of heat

Question 33

Revers reaction producing n2 and h2 gas=

Answer 33

Endothermic b/c absorbs energy from surroundings

Question 34

Purifying copper by electrolysis process

Answer 34

1. A beaker with pure and impure copper rods are dipped into copper sulfate solution 2. Pure copper is connected to negative terminal of battery and impure copper is connected to positive terminal 3. Pure copper rod increases in size, while impure cooper rod has shrinked, leaving a pool of anode sludge at bottom of beaker

Question 35

Extraction of aluminium process

Answer 35

1. Purify the bauxite ore by crushing it and mixing it with sodium hydroxide - aluminium oxide reacts with sodium hydroxide and dissolves 2. Aluminium needs to be molten but aluminium oxide melts at 2070 degrees-> dissolved in cryolite to lower mp for electrolyte 3. Carbon electrodes are used during electrolysis - aluminium metal forms on cathode - oxygen gas forms on anode 4. @cathode: aluminium ions reduced to aluminium metal and falls to bottom of cell and is removed - Al 3+(l) +3e—> Al(l) 5. @anode: oxide ions oxidised to oxygen - 2O 2–> O2 +4e-

Question 36

Side reaction during extraction of aluminium

Answer 36

C(s)+ O2-> CO2 (g)

Question 37

Haber process

Answer 37

1. Obtain reactants and mix them in 3:1 ratio (H:N) 2. Set conditions in the sealed container so equilibrium can be reached 3. Cool reaction mixture so ammonia condenses and can be removed and collected 4. H2 and N2 gases are recycled back into reaction vessel

Question 38

Obtain reactants of Haber process from

Answer 38

N2: fractional distillation of air H2: natural gas, cracking of ethane

Question 39

Conditions required for Haber process

Answer 39

Iron catalyst High temp of 450 degrees High pressure 200 atm

Question 40

Why will n2 and h2 not condense when ammonia is cooled

Answer 40

B/c ammonia gas has a higher mp and bp so cooling system to ammonia’s bp will not condense n2 and h2

Question 41

Equilibrium definition

Answer 41

Rate of Forward reaction= rate of backward reaction

Question 42

Nitric acid

Answer 42

HNO3

Question 43

Phosphoric acid

Answer 43

H3PO4