BMAT Chemistry

Question 1

position of transition metals in periodic table

Answer 1

d-block

Question 2

common properties of transition metals

Answer 2

coloured ions
multiple stable ions
used as catalysts

Question 3

physical properties of group 1 metals

Answer 3

soft metals

relatively low MP and BP for metals

Question 4

why do group 1 metals need to be stored in oil

Answer 4

due to high reactivity they oxidise in moist air

Question 5

noble gases

Answer 5

group 18

v unreactive- least reactive elements

Question 6

why are noble gases unreactive

Answer 6

they have full outer shells

Question 7

how can miscable liquids be separated

Answer 7

fractional distillation
paper chromatography (non volatile liquids)

Question 8

how can immiscable liquids be separated

Answer 8

separating funnel

Question 9

how can a soluble solid be separated from insoluble solids

Answer 9

dissolving
filtration
evaporation/distillation
crystallisation

Question 10

what is a monoprotic acid

Answer 10

acid that can only donate 1 H+
di=2
tri=3
poly=many

Question 11

what is a monobasic acid

Answer 11

has only one hydrogen ion to donate to a base in an acid-base reaction

Question 12

why is electrolysis DC not AC

Answer 12

if AC the anode and cathode would be constantly changing

Question 13

what happens in electrolysis

Answer 13

cations reduce by gaining electrons at cathode

anions oxidise by losing electrons at anode

Question 14

anode

Answer 14

+ive electrode

Question 15

cathode

Answer 15

-ive electrode

Question 16

anion

Answer 16

-tive ion

Question 17

cation

Answer 17

+tive ion

Question 18

common uses of alcohols

Answer 18

alcoholic beverages (ethanol)
disinfectant (rubbing alcohol)
cleaning detergents (breaks down lipids)
fuel

Question 19

common uses of carboxylic acids

Answer 19

making esters
making vinegar (dilute ethanoic acid)

Question 20

explain electrolysis of brine

Answer 20

NaCl (aq) = brine
hydrogen gas produced at cathode as Na+ reduces into Na which reacts to form NaOH
chlorine gas produced at anode as Cl- oxidises into Cl2

Question 21

electrolysis of brine half equations

Answer 21

cathode: 2H+ + 2e- arrow H2
anode: 2Cl- - 2e- arrow Cl2

Question 22

overall equation for electrolysis of brine

Answer 22

2NaCl(aq) + 2H2O(l) arrow 2Na+(aq) + 2OH-(aq) + Cl2(g) + H2(g)

Question 23

what is electroplating

Answer 23

Electroplating involves using electrolysis to put a thin layer of a metal on the object:

the cathode is the iron or steel object
the anode is the plating metal
the electrolyte contains ions of the plating metal

Question 24

explain electroplating using copper (copper sulfate)

Answer 24

the cathode is pure copper-at the cathode, copper ions from the electrolyte gain electrons and become copper atoms
the anode is impure copper, produced from copper ore-at the anode, copper atoms lose electrons and become copper ions in the electrolyte
the electrolyte is copper(II) sulfate solution

Question 25

electrolysis of copper sulfate half equations

Answer 25

Cathode reaction: Cu2+(aq) + 2e- → Cu(s)

Anode reaction: 2H2O(l) → O2(g) + 4H+(aq) + 4e-

Question 26

what happens in electrolysis of copper sulfate if the electodes are graphite?

Answer 26

With carbon (graphite) electrodes, the oxygen usually reacts with the anode to form CO2.

Question 27

overall equation for electrolysis of copper sulfate

Answer 27

2CuSO4 (aq) + 2H2O (l) → 2Cu (s) + 2H2SO4 (aq) + O2 (g)