80% is quite solid, especially for a school like nsg. A raw mark of 83 usually aligns to a band 6 in the hsc, so you still have plenty of time to improve
The equivalence point is around 8 pH which lines up to a volume added of 22mL.
22mL is the amount of sodium hydroxide added against acetic acid. As always, write out a balanced equation for this reaction.
Then, you can calculate the number of moles of NaOH which is 0.022L x 0.15 mol/L =...
Question 9:
The two organic compounds are CH3CH2COOH (propanoic acid) and HOOCH (methanoic acid). They both contain a carboxyl functional group which is organic due to the presence of carbon. As such, the answer cannot the HCl nor H2SO4. HCN is not organic acid because there is no -COOH group.
Question 8:
Ethanol and methanoic acid will reflux to produce ethyl methanoate (an ester). You should first write out an equation for this
Determine the number of moles of both ethanol and methanoic acid. This can be done by using n = m/MM
n(ethanol) = 3.50g / 46.068 g/mol = 0.07597 mol...
what are your internal ranks? You'd have to do exceptionally bad to get an atar below 75 (i'm talking around getting 60-70 range for each of your subjects).
Definitely still possible to get somewhere in the low 90s to mid 90s. You still have a your externals which is worth 50% of your HSC. However, I'm not going to sugar-coat it, you will have to do extremely well in your external exams (around raw marks of 85). Being out of the top 10 in a school...