BMAT Chemistry Flashcards
position of transition metals in periodic table
d-block
common properties of transition metals
coloured ions
multiple stable ions
used as catalysts
physical properties of group 1 metals
soft metals
relatively low MP and BP for metals
why do group 1 metals need to be stored in oil
due to high reactivity they oxidise in moist air
noble gases
group 18
v unreactive- least reactive elements
why are noble gases unreactive
they have full outer shells
how can miscable liquids be separated
fractional distillation paper chromatography (non volatile liquids)
how can immiscable liquids be separated
separating funnel
how can a soluble solid be separated from insoluble solids
dissolving
filtration
evaporation/distillation
crystallisation
what is a monoprotic acid
acid that can only donate 1 H+
di=2
tri=3
poly=many
what is a monobasic acid
has only one hydrogen ion to donate to a base in an acid-base reaction
why is electrolysis DC not AC
if AC the anode and cathode would be constantly changing
what happens in electrolysis
cations reduce by gaining electrons at cathode
anions oxidise by losing electrons at anode
anode
+ive electrode
cathode
-ive electrode
anion
-tive ion
cation
+tive ion
common uses of alcohols
alcoholic beverages (ethanol)
disinfectant (rubbing alcohol)
cleaning detergents (breaks down lipids)
fuel
common uses of carboxylic acids
making esters making vinegar (dilute ethanoic acid)
explain electrolysis of brine
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
electrolysis of brine half equations
cathode: 2H+ + 2e- arrow H2
anode: 2Cl- - 2e- arrow Cl2
overall equation for electrolysis of brine
2NaCl(aq) + 2H2O(l) arrow 2Na+(aq) + 2OH-(aq) + Cl2(g) + H2(g)
what is electroplating
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
explain electroplating using copper (copper sulfate)
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
electrolysis of copper sulfate half equations
Cathode reaction: Cu2+(aq) + 2e- → Cu(s)
Anode reaction: 2H2O(l) → O2(g) + 4H+(aq) + 4e-
what happens in electrolysis of copper sulfate if the electodes are graphite?
With carbon (graphite) electrodes, the oxygen usually reacts with the anode to form CO2.
overall equation for electrolysis of copper sulfate
2CuSO4 (aq) + 2H2O (l) → 2Cu (s) + 2H2SO4 (aq) + O2 (g)
