These are the equations you need in your toolbox to support
your answers in the HSC. Some are handy to push for the high marks in extended
response questions. Some are VITAL to know (eg 3, 4, 7, 8, 10, 11, 12, 14, 17,
18, 19) to achieve the basics of the course.
If you are having trouble remembering them – try to think of
them in context. Eg remember what happened in your fermentation experiment,
remember how we decarbonated soft drink, remember how ozone blocks UV rays and
why CFC’s decompose ozone etc
Click on the images for a larger version.
1) Addition polymerisation
eg PVC
HINT
Show 2n monomers so you can show the repeating
structure of the polymer chain. NB the square brackets to signify the repeating
unit
2) Polymerisation of glucose to form cellulose
HINTS
1) If
you need help remembering the structure of glucose – let me know – I’ve taken a
few people through it and it is (for the most part) working
2) Every
second glucose is inverted.
3) Being
a condensation polymerisation there is a water molecule produced for each link
– there is always one less link than monomers (think about why) thus there is
always one less water molecule than monomers.
4) Showing
four glucose monomers is ideal to illustrate the above but under time pressure
two would suffice as long as you note that every second one is inverted.
3) Addition of bromine water to cyclohexene
HINTS
1) use
the carbon chemistry shorthand – ie don’t bother drawing the C and H atoms
2) Bromine
water is an aqueous solution, but cyclohexene and 1,2-dibromocyclohexane are
non-soluble in water so are liquids.
4) Fermentation
HINTS
1) you
*SHOULD* know that ethanol and carbon
dioxide are products, that the glucose needs to be aqueous and yeast is
required. We do the experiments (and you learned all about ethanol production) so
you don’t need to think about these things – you should just remember.
2) If
you know the products then it is just a simple case of remembering that there
are TWO of each product.
3) This
is one of the only reactions involving carbon compounds where you don’t need to
use structural equations
5) Combustion of an alkanol
eg ethanol
HINTS
1) For
all hydrocarbon combustions – balance carbon, then hydrogen, then oxygen (CHO)
2) Remember
that there is an oxygen in the alkanol so you need one less oxygen than normal
(ie one of the reasons why ethanol has such complete combustion)
6) Incomplete combustion
eg ethanol
HINTS
1) The
simplest incomplete combustion is where C(s) is the only product
2) Use
CHO
7) Dry cell reactions
HINTS
1) Never
hate mangoes watery monkey nuts
2) You
should know that ammonium has a charge of +1 (it is the ‘t’ in hate)
8) Silver cell reactions
HINTS
1) The
silver and zinc reactions are basically opposites of each other
2) The
oxide and hydroxide must be on opposite sides of the equations
3) Hydroxide
is consumed at the anode and produced at the cathode
9) Radioactive decay
HINTS
1) RULE
1 – If Z > 82 = alpha emitter
2) RULE
2 – If n/p is too high = beta emitter
Z < 20 :
n/p = 1:1
Z ~ 50 :
n/p = 1.3:1
Z ~ 80 : n/p = 1.5:1
Eg 1) C-14
C has 6 protons
Thus there are 14-6 = 8 neutrons
n/p = 1.33:1 – too high s it should be 1:1 – thus it is a
beta emitter
Eg 2) Hg-210
Hg has 80 protons
Thus there are 210-80 = 130 neutrons
n/p = 1.625:1 – too high should be 1.5:1 – thus it is a beta
emitter
Eg 3) Sn-115
Sn has 50 protons
Thus there are 115-50 = 65 neutrons
n/p = 1.3:1 – just right = stable
Eg 4) At-217
At has 85 protons – thus it is an alpha emitter
10) Acid rain
HINT
All you have to show is that it forms an acid – thus if you
can show sulphur dioxide forming sulfurous acid or nitrogen dioxide forming its
mixture of nitric and nitrous acid you can stop
11) CO2 solubility
HINTS
1) Generally,
non-polar covalent molecular compounds do not dissolve in water. Carbon dioxide
is an exception because it REACTS with water
2) The
reaction is as simple as just adding the atoms of carbon dioxide and water
together – remembering to use an equilibrium sign!
12) Citric acid
HINTS
1) Remember
that it is the oxygen of the hydroxyl group that bonds to the carbon
2) Carboxylic
acid groups have a double bonded oxygen and a hydroxyl group
13) Esterification eg
pentyl ethanoate
HINTS
1) Remember
it is EQUILIBRIUM
2) Remember
that it needs a concentrated sulfuric acid catalyst
3) Remember
that is produces water
4) Remember
that primary alkanols from propanol onward need to end with ‘…an-1-ol’
14) Haber equilibrium
HINTS
1) Know
the formula of ammonia
2) Know
that it comes from hydrogen and nitrogen gas
3) Balance
the equation
4) Know
that it is in equilibrium
15) Ozone
HINTS
1) When
writing the ozone equilibrium always show O3 absorbing UV – this is so you can
explain how the ozone layer absorbs UV
2) It
is good practise to label the coordinate covalent bond for ozone
(distinguishing the electrons from each oxygen is also useful)
16) CFC’s decomposing ozone
HINT – to show that it is a catalyst for ozone decomposition
you must show them reforming (ie catalysts provide a reaction pathway that
lower the activation energy but are not consumed in the reaction).
17) Rusting
HINT – if you want to do well in the shipwrecks option you
need to know these four equations. They can be used to explain just about
everything about the factors that effect rusting and rust protection systems
18) Sulfate reducing bacteria
HINT – Soloh ate his two sneakers for water. Need I say
more?
19) Precipitation
HINTS – This is as simple as I can make the solubility rules
for the HSC
1) All
Group 1 metal, ammonium, nitrate, acetate (and phosphate in acidic conditions)
compounds are SOLUBLE
2) All
other carbonates and phosphates are INSOLUBLE
3) Chlorides
are soluble except lead and silver
4) Hydroxides
are soluble except lead, silver, iron and copper
5) Sulfates
are soluble except for lead, silver, barium and calcium
6) Carbonates
bubble in acid
7) Flame
tests – barium = apple green, calcium = brick red, copper = emerald green