hi deloso, most of my knowledge has just come from understanding and not actually rote learning. I've actually done quite little learning from textbooks, booklets etc. I don't believe chemistry gets many questions where you need to 'conceptualise' can you provide me with a few examples? Thanks.
+1 i need help with this too
can you give me a specific question?
Kittyful this graph works on the basis that a strong base + a strong acid = neutral salt, a strong base + weak acid = basic salt, a strong acid + weak base = acidic salt. When doing questions like this, where they present you with a graph, you want to look at the points where it drops, at the middle of this "dropping" is the equivalence point and the eq. point is indicative of the pH of the salt. In this case, if you get a rule and measure the midpoint of the dropping in the solid curve, you can notice that the midpoint is around 7, therefore the salt is neutral because of this we know that the reaction was between a strong base and strong acid (it could also be weak base weak acid), we then look at the dotted curve, and do the same method.. we measure the midpoint and notice it lies around 5. This shows that the salt is acidic and was therefore made from a strong acid and weak base. =)
that's good then.
In working with oxidation states you need to understand valency. When looking at the change in oxidation state of manganese we first start off by looking at MnO2. We know that the oxidation state of oxygen is -2 because of its valency, there are also 2 oxygens therefore oxygen is -4, to balance this manganese must be +4 as the overall charge of the compound is neutral. We then look at Mn2O3 - using the same method oxygen is -2, you times this by 3 and get -6, you have 2 manganese which have to equal +6 to balance this out. so one manganese must be +3. =)How would you answer this oxidation state question ... i kinda don't understand how you do these questions
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answer is B
Ahh yeah fair enough, yeah some questions are quite challenging but my concepts are fairly well grounded. CSSA trial is tmoz, im hoping that its all doable =). good luck studying.
Never seen those terms in the syllabus.
you get bonus marks for mentioning it
Uh, wouldn't do anything to the temperature.. it would disrupt the equilibrium, releasing more CO2 gas.
yes indeed 100% needed - see it in EVERY single CSSA exam =) hahaha
CO2(g) + H20(l) <==> H2CO3(aq)
hmm very nice explanation, I admit i was wrong.
