UCAS Mock

Question 1

What is the volume of one mole of a gas?

Answer 1

24dm-3 or 24000cm-1

Question 2

Calculate gas volume using moles

Answer 2

Volume = moles x 24

Question 3

Avogadros constant

Answer 3

6.02 x 10^23

Question 4

Ideal gas equation

Answer 4

pV = nRT

Question 5

Units for ideal gas equation

Answer 5

p = Pa
V = m^3
T = Kelvin

Question 6

Calculating mean titre things to remember

Answer 6

• only use concordant results (within 0.1cm^3 of each other)
• don’t include the rough titre

Question 7

% yield

Answer 7

Actual / theoretical

Question 8

Oxidation number of group1

Answer 8

+1

Question 9

Oxidation number of group 2

Answer 9

+2

Question 10

Oxidation number of group 7 ions

Answer 10

-1 if alone but can be variable

Question 11

Oxidation number of oxygen

Answer 11

-2 unless in peroxide

Question 12

Oxidation number of hydrogen

Answer 12

+1 unless in a metal hydride

Question 13

Oxidation number of fluorine

Answer 13

ALWAYS -1

Question 14

Energy change

Answer 14

q = mcΔT (in joules)

Question 15

Test for carbonate ions

Answer 15

Add nitric acid
- if positive test, there’s effervescence as CO2 is produced
- test gas with lime water to confirm

Question 16

Test for sulfate ions

Answer 16

Add aqueous barium chloride
- positive test: white precipitate formed (BaSO4)

Question 17

Test for halides

Answer 17

Add aqueous silver nitrate
- positive test: precipitate formed

Question 18

How to identify the precipitate formed in halide test

Answer 18

White - silver chloride
Cream - silver bromide
Yellow - silver iodide

Question 19

How to confirm halide tests if colours are difficult to determine

Answer 19

Dilute NH3: AgCl is soluble, AgBr and AgI are insoluble
Conc NH3: AgBr is soluble, AgI is insoluble

Question 20

Test for ammonium ions

Answer 20

Heat with NaOH(aq)
- positive test, OH- reacts with NH4+ forming NH3(g) which you test with damp indicator paper (alkaline)

Question 21

Group 2 + oxygen

Answer 21

Group 2 metal oxide

Question 22

Group 2 + water

Answer 22

Group 2 metal hydroxide + hydrogen

Question 23

Group 2 + dilute acid

Answer 23

Group 2 metal salt + hydrogen gas

Question 24

Group 2 oxide + water

Answer 24

(Group 2 ion)^2+ + 2OH-

Question 25

How are group 2 reducing agents

Answer 25

Donate electrons, other species are reduced

Question 26

Trend in group 2 reactivity

Answer 26

Increases down group Atomic radius and electron shielding increase (more shells) Less attraction between outer electron and nucleus

Question 27

Solubility and PH trend in group 2 hydroxides

Answer 27

Increase down group

Question 28

Solubility and PH trend in group 2 sulfates

Answer 28

Decreases down group

Question 29

Uses of calcium hydroxide

Answer 29

Lime - neutralise acidic fam soil for crops

Question 30

Medical uses of group 2

Answer 30

- indigestion tablets neutralise excess stomach acid (Mg(OH)2 = milk of magnesia and CaCO3) - barium meal for x-rays

Question 31

Why are group 7 known as oxidising agents

Answer 31

Gain electrons causing other species to be reduced

Question 32

Colour of halogens in water

Answer 32

Cl - pale green Br - orange I - brown

Question 33

Colour of halogens in cyclohexane

Answer 33

Cl - pale green Br - orange I - purple/ violet

Question 34

Displacement of halogens

Answer 34

Reactivity decreases down group - chlorine displaces bromine + iodine - bromine displaces iodine

Question 35

Water purification using chlorine

Answer 35

Cl2 + H2O —> HClO + HCl - HClO acts as a weak bleach that kills bacteria

Question 36

Water purification using chlorine

Answer 36

Cl2 + H2O —> HClO + HCl - HClO acts as a weak bleach that kills bacteria

Question 37

Benefits and risks of using chlorine in the water purification

Answer 37

Benefits: – Cleans water makes it safe to drink Risks: – chlorine is a toxic gas, can react with hydrocarbons to form chlorinated hydrocarbons, which are suspected of causing cancer

Question 38

Benefits and risks of using chlorine in the water purification

Answer 38

Benefits: – Cleans water makes it safe to drink Risks: – chlorine is a toxic gas, can react with hydrocarbons to form chlorinated hydrocarbons, which are suspected of causing cancer

Question 39

Dissociation of a strong acid

Answer 39

irreversible reaction (One way reaction)

Question 40

Dissociation of a weak acid

Answer 40

Reversible reaction

Question 41

Acid + alkali

Answer 41

Salt + water

Question 42

Metal oxide + acid

Answer 42

Salt + water

Question 43

Metal hydroxide + acid

Answer 43

Salt + water

Question 44

Metal carbonate + acid

Answer 44

Salt + water + carbon dioxide

Question 45

Neutralisation ionic equation

Answer 45

OH-(aq) + H+(aq) —-> H2O(l)