Last minute tips for Paper 2 (based on mistakes I made)

1. Make your answers specific.

E.g. “Al has a lower first IE than Mg because the valence electron of Al is in a higher energy orbital” is NOT good enough. You need to mention Mg’s valance electron being in 3s and Al being in 3p (specifically 3s and 3p for this particular case) and the shielding and whatnot.

Other common slips:

- WEAK Van der Waals’ forces

- STRONG covalent bonds

- Lower ionisation energy of (named element)…

- CO boiling point greater than N2 because CO has dipoles (saying it is polar is not enough)

- (Primary/Secondary/Tertiary) alcohol, (nucleophilic, electrophilic) substitution…

- COLOUR of chlorine gas disappears

- Cl is a strong oxidising agent (when explaining why CuCl2 is formed, but not CuCl when Cu is reacted with Cl2)

- Heat STRONGLY in a boiling tube

- HCl is used in excess (reacting with NaOH) to ensure COMPLETE NEUTRALISATION (to ensure all NaOH is reacted is not usually enough)

2. Make your answers comparative when necessary

Reaction of NaOH and HCl is almost instantaneous in comparison to the reaction of 2-bromopropane and NaOH, which requires heating for several minutes. Give explanation of why these reactions are different. (Paraphrased from 2016 specimen paper)

Reaction 1 (NaOH + HCl): Reaction involves ions, opposite charges attract. (You could probably elaborate a bit on the ease of dissociation too)

Reaction 2: Greater Ea. Energy required to break COVALENT bond is greater.

Other examples:

- Permanent dipole-dipole attraction STRONGER THAN Van der Waals’ forces

- Number of electrons decrease (in forming cations), but number of protons remains constant (explaining lower radius of cations of elements than atoms)

- RHS of equilibrium has lower volume, equilibrium shifts to the LHS, etc.

- Hydrogen bonds are weak in comparison to covalent bonds, but strong in comparison to permanent dipole-dipole attraction. State whether the bond is weak or strong when comparing the two.

3. MEMORISE ALL TRIVIAL THINGS

pH values of oxides dissolved in water, disproportionation reaction of Cl2 with NaOH, amphoteric reactions of Al2O3 (HCl and NaOH), compound formed when AgX is dissolved in NH3 (When X is a halide) the compound is Ag(NO3)2X or alternatively, the ion formed is Ag(NO3)2

+. Memorise it all somehow. Trends of solubility and thermal stability of carbonates and hydroxides come under that too. So does definitions. MEMORISE ALLLLLL.

4. Don’t lose marks on the small details and specifics

Positive charge when drawing an NH4+ 3D structure, sketch of 2s orbital must be bigger than 1s,

weak Van der Waals’ forces, (…) at standard conditions (for standard enthalpy change),

Rules of 9701 learned from experience

1. When in doubt, blame activation energy

2. Unfamiliar questions in chemistry ALWAYS relate to known properties of functional groups, trends, etc.

3. Just like chemistry, the questions they ask show trends. (hahahahaha…) Familiarise yourself with the trends by reviewing the past years. Know what they’re asking for.

4. Overthinking unfamiliar questions usually ends badly.

5. When they say “… data from the Data Booklet” or “using equations”, the data or equations contribute to quite a big chunk of the marks. Especially equations. Chemists love equations so much they might as well be mathematicians.

6. Details details details. Details make up about 15% of each question (based on the average marks I lose because of details per paper). Don’t lose those valuable marks. Precise and accurate.

7. Like Mr. Amran said, you’re not doing English Literature. Short and simple answers within the provided lines should be sufficient for getting full marks.

8. Don’t overthink.