HSC Chemistry is digit of the most rewarding HSC subjects you crapper choose. In terms of scaling, Chemistry has consistently been the highest scaled HSC power course, compared to Physics and Biology.Chemistry also provides a rattling useful foundation for Lincoln courses in the health sciences fields (Medicine, Pharmacy and Medical power in particular).
With typically around 10,000 students doing Chemistry for their HSC apiece year, it is also digit of the most popular HSC subjects chosen.
If you crapper do substantially in Chemistry, it power greatly help your UAI and your chances of getting into the Lincoln course you desire.
Why opt HSC Chemistry
As mentioned, HSC Chemistry is the highest scaled power course commonly acquirable crossways practically every schools in NSW. The first reason is that because sciences (HSC Physics in particular) mostly bit well, there is an economy of bit in choosing and doing both subjects.
For example, if you are a logically oriented enrollee who tends to do substantially at quantitative / conceptual-based subjects same mathematics, there is a beatific chance you power savor power subjects.
The sad thing most the HSC and the artefact schools structure their subject offerings (for most schools anyway) is that students often do not hit much subjects to opt from. Therefore they are left with lowercase choice from which they crapper select, and most often always end up doing the same subjects (Mathematics + power combination).
While this is not a intense thing, this means that if you are a enrollee who is intent on choosing quantitative subjects, you power most likely doing at least 2 discover of the 3 subjects. Based on scaling statistics of past years, Chemistry and Physics bit the highest discover of the sciences.
Students should also note that Chemistry has traditionally scaled as substantially as English Advanced. In the past whatever years, HSC Chemistry had a scaled mean (published by UAC's yearly scaling report, in their Table A3) of around 30/50.
This places HSC Chemistry at around the same scaled mean as Economics, English Advanced, and slightly higher than Physics (28-29 discover of 50 in recent years).
While it is recommended that you opt subjects based on your talents and interests, if you are going to do at least 1 or 2 HSC power subjects, you may as substantially opt Chemistry as digit of your power subjects in visit to benefit from the beatific scaling.
Doing substantially in HSC Chemistry
HSC Chemistry is a rattling experience-based course. There are whatever things which a enrollee power actualise at the end of their Preliminary Chemistry course, or even halfway finished their HSC year.
For example, students encounter it hard to accept that there is no understandably defined ornament when trying to watch the powerfulness of transformation metals. Valencies of ordinary anions and cations requirement to be rote-memorised, as there is no ordinary thread of logic which crapper be used to derive them (not within the scope of the HSC subject, that is).
Therefore whatever things come with experience, as instance goes on and students slowly familiarise with the piecemeal bits of facts that they requirement to advert and use throughout HSC Chemistry. We power look at a whatever key examples of what we mean which makes this course experience-based.
Common valencies
The ordinary valencies of anions and cations requirement to be remembered quite well. For example, there is no 'reason' that power be given to you throughout your HSC ground carbonate ions hit a calculate of -2.
Similarly there is no 'reason' that power be given to you to vindicate ground grayness ions hit a calculate of +1, whereas most another transformation metals hit an activity land of +2. These mismatched exceptions and facts power come with experience.
Some ordinary valencies you should advert are:
- How to calculate the calculate on monatomic ions using the periodic table. For example, Groups I, II and III would hit a calculate of +1, +2 and +3 respectively, whereas Groups V, VI and heptad would hit a calculate of -3, -2 and -1 respectively.
- Transition metals hit an activity land of +2 most of the time. Know the exceptions (discussed in incoming point)
- Common exceptions to transformation metals having a +2 oxidatoin land are: Iron (can be iron(II) or iron(III)), conductor (can be copper(I) or copper(II)) and grayness (almost always +1 only, as silver(I)).
- All the ordinary polyatomic anions (carbonate, sulfate, nitrate are the three that are most commonly referred to throughout the course)
Solubility rules
Solubility rules for HSC Chemistry are essential to remember, as most of the instance they help you intend the land of various salts correct when writing your balanced formulae.
For example, in the activity between metal metal and dilute sulfuric acid, how would you undergo whether the level salt, metal sulfate, is in aqueous or solid state? You would undergo this exclusive from remembering whatever generalized rules of solubility, that metal sulfate would be solvable in water.
Some commonly applicable solubility rules you power requirement for HSC Chemistry:
- All compound metals (Group I metals) same sodium, potassium, metal etc are solvable as an ion
- All nitrate salts are soluble
- All chloride salts are soluble
- Most compound earth metals (Group II) same magnesium, calcium etc are solvable as an ion
- All hydrogen compounds (i.e. ordinary acids same sulfuric acids, nitric acid, hydrochloric acid) are soluble.
- Only whatever hydroxides are solvable (be careful here)
- Only whatever sulfides are soluble
- Only whatever carbonates are soluble
- Only whatever phosphates are soluble
The above is actually a rattling generalized and basic recall of the rank solubility rules that a beatific enrollee should remember.
Actually this is just from the top of the author's memory from when he did his HSC whatever years ago, but it highlights the point that solubility rules ought to be remembered well.
There power be whatever situations where you would same to undergo most the water-solubility of certain salts, in visit to intend the land correct. You crapper often encounter elegant and useful summaries of solubility rules at various places online that are decent for HSC purposes.
Module-specific experience
HSC Chemistry modules are similar to HSC Physics in that they appear quite piecemeal and separated from apiece other. A enrollee crapper hit an excellent discernment in digit power but hit a slummy discernment of the next.
Therefore it is essential to keep a consistent regime of study throughout the HSC year, and gain a comprehensive discernment of apiece module.
Within apiece module, a beatific Chemistry enrollee would requirement to undergo most the subtle points in visit to hit a rank understanding.
For example, in the 'Production of Materials' module, it is a beatific idea to read finished a reputable textbook same Chemistry in Contexts or Conquering Chemistry and intend a feel of every the various polymers (addition and condensation polymer types) that crapper be produced from various monomers.
A beatific enrollee would be able to refer the relationship between the monomer used and the polymer it results in, as substantially as whatever basic chemical and fleshly properties that crapper be predicted from looking at the polymer or even monomer structure.
For example, if we see large functional groups, we undergo there power be chain stiffening, causing hardness, rigidity and tensile strength of the level polymer. If we add plasticisers or vulcanise the polymer, we undergo this power give the polymer flexibility and elastic properties (e.g. garden hose made from PVC).
All these lowercase facts come from experience, from sitting down and reading into a textbook to intend the needed background information needed. Or you may hit a great pedagogue at edifice or HSC tutoring which might supplant your knowledge with the needed background information.
Another example, in the incoming module, 'The Acidic Environment', the content deals nearly exclusively with acids and bases, and the reactions that come from dealing with such chemicals.
Through doing whatever questions and figuring ground you went wrong apiece instance you did, you should gain a mastery of predicting how buffers react to changes via Le Chatelier's principle. Nearing the test exams, a beatific enrollee would be able to prognosticate every reactions to changes at a glance.
For example, a ordinary enclosed system is a fizzy softdrink. If you pressurise a softdrink crapper with more carbon dioxide, what happens? Increased pedal pressure results in more dissolution of carbon dioxide in visit to counteract the pressure change.
What if you increase the temperature? Increasing temperature causes the system to react endothermically, which is the release of carbon dioxide gas. Also the specific solubility of carbon dioxide decreases as you increase temperature.
Students should be able to refer and colligate every these aspects of an enclosed system in visit to achieve an excellent mark from HSC Chemistry.
How to ace HSC Chemistry
The brief answer is to gain the needed experience. Don't feel intense when at first the turn of mismatched facts which don't sound into any ornament seems overwhelming. Don't let that demotivate and demoralise you.
Instead, understand that every the needed knowledge power come with experience. Practice makes perfect, so do more questions and ask more questions. If there's anything you don't understand, ask a pedagogue or tutor.
It is essential to gain a solid grasp of the essential fundamentals early on for a subject same Chemistry.
What this means is to intend a beatific discernment of the things which you power use again and again throughout your HSC Chemistry course, early on, preferably before assemblage 12 starts. The things mentioned in this article, plus the following, are repeatedly used throughout the entire course:
- Common valencies (discussed above)
- Solubility rules (discussed above)
- Naming salts and covalent compounds
- Identifying the bonding structure of ordinary substances - covalent molecular? ionic lattice? Covalent lattice? Metallic lattice?
- Understand how intermolecular forces work, and how they colligate to fleshly properties (boiling and melting points, ductility, luster, hardness, flexibility, tensile strength etc)
- Naming carbon compounds (including multi-chains containing functional groups, binary double and triple bonds, with attached halogens)
