Chemistry Practice Trial RANT

Rant time - cannot sleep so I'd better get this off my chest.

There is nothing more frustrating for me than to spend considerable time having attended numerous teaching development days and events to learn what it takes to ace the HSC, then spend long hours (cue tiny violins) marking drafts, correcting portfolio's, running tutorials and STRONGLY emphasising key points about the Chem syllabus and HSC to have the same mistakes made over and over again.

If you are making mistakes like this you really need to ask yourself why - if you don't understand a concept then what are YOU actually doing to remedy this. If you do understand the concepts and suggestions given then you really need to think carefully about whether you really are giving your best.

That said - hopefully this practise trial will be a bit of a wake up - the real trial will be better and show some areas for growth and you can peak in time for the HSC.

#1) Mole style Q - there are only so many mole style Q they can ask. I have done my best to demonstrate and have practise at each one throughout the last two terms. We will do more but really, all that is left is practise. If you know this is an area of weakness, what are YOU doing about it? You have the B Hegarty book. You have my study notes that map out the numerical dot points to HSC Q. You have the Success One book with the said Q. If you are serious about improving set aside 6 minutes per night and do 3 marks worth of mole Q. Once you have done them all - go back and do the ones you got wrong. If you get them wrong again ask for advice. Repeat until done. I cannot make it simpler than that.

#2) If multiple choice is your weakness go to the BOS site and do 5 marks worth of MC every night (and use Success One for 2010 & 2011). Once done repeat. Very soon you will see some common tricks and you will be 'immune' to the common traps.

#3) Get your structural diagrams right and get your states right and NEVER write an incorrectly balanced equation

#4) Know the difference between diagnostic and therapeutic use of radioisotopes and know that gamma rays mostly pass straight through the body = very good for diagnosis as  = no harm and they can exit the body to be detected.

#5) For amphiprotic examples - if you want to show it acting as a proton donor (acid) show it reacting with OH-. If you want to show it acting as a base (proton acceptor) show it reacting with H3O+. Only show it reacting with water IF you know whether it specifically acts as an acid or base with water

Eg bicarbonate reacts with OH- as an acid, H3O+ as a base and water as a base (water is a stronger proton donor than bicarbonate so in the water solvent bicarbonate is a base) eg
HCO3- + H2O => H2CO3 + OH-  (hence pH > 7).

#6) When analysing equilibrium curves REFER to LCP & state all the trends of the curve ESPECIALLY the last often forgotten bit (that links to LCP) "...and a new equilibrium is established."

#7) A yellow smoky combustion flame means C(s) produced - so make sure this is reflected in any equation you write.

#8)  Haber - ALWAYS work this in somewhere once you have explained LCP and rate etc " A magnetite catalyst is used so that higher rates can be achieved at lower temperatures where the yield is higher. This increases the overall output of ammonia and profit made by the Haber plant.".

#9) Titles on graphs, show data points and draw a single line of best fit.

#10) When talking about AAS you must say its accuracy - that is the whole point - and why this accuracy needed eg "AAS is accurate down to ppb. This is important when monitoring heavy metals (or trace elements) as their effects become apparent when in concentrations as low as a few ppm and thus are too low to be accurately monitored using traditional wet chemistry (gravimetric) techniques."

#11) When giving a case study for our heavy metal (lead) ALWAYS say its source and its detrimental effects on the body.

#12) Elective - If you ever get a Q about history of elecrochem - or a Q about any one of Galvani, Volta, Davy and Faraday - even if the Q is bizarre at LEAST spell out what each scientist did with respect to electrochem. We did it in class, we wrote an essay on it. Just do it. And for the record Faraday not only came up with the quantitative Laws of Electrolysis that helped make electrochemistry valuable to industry and research (linking charge, mass and valency) but also developed the TERMINOLOGY to communicate about electrochemistry.

#13) Technically oxygen solubility is higher at low temperatures and high pressures. BUT in there deep ocean where there is low temp and high pressure there is no (or little) oxygen to dissolve anyway so these factors have little impact on the oxygen content of the ocean - what does make a difference is the wave mixing and photosynthesis at the surface making oxygen near saturation, but the steadily decreasing photosynthesis, slow diffusion and increasing respiration and decomposition reactions that steadily decrease oxygen (with a small bump near the bottom due to deep ocean polar currents).

 Hopefully when you look at these suggestions - there is nothing there that you cant do. Just need the practise, practise, practise to make sure that you do them naturally.