What are the different types of JC Chemistry tuition classes available at your centre?

We have 3 modes of learning for students to choose from: weekly physical classes at Bishan; weekly online lessons via Zoom; and on-demand video lessons.

Are you the only Chemistry tutor conducting the classes or do you engage other tutors to do that?

Please be rest assured that I conduct all my classes personally and I do not engage other tutors to teach at my centre.

What is your class size at Bishan?

Usually the class size is around 10 to 12 students. Max class size is 16 pax.

Is there makeup lesson if I miss a class?

Yes makeup lesson is available in the same week subject to availability. If makeup class is not possible, the student can view the recorded video lessons at Google Classroom.

Do you have trial lesson available? How much is it?

Yes we do. Fees for trial lesson are for Bishan class and for Zoom online class.

Does your centre offer O Level chemistry tuition? Do you teach IB / IP chemistry tuition? How about H1 Chemistry?

Chemistry Guru specialises in H2 Chemistry for JC1 and JC2 or IP Year 5 and IP Year 6 students only. Find out all the information about A Level H2 Chemistry and the detailed comparison between H1 and H2 Chemistry. We do not conduct lessons for H1 Chemistry, O Level Chemistry, IB Chemistry or IP Chemistry at IP Year 3 and IP Year 4.

2024 A Level H2 Chemistry Paper 1 Solutions - Questions 1 to 10

Question 1

2024p1 q1

Answer: D

Topic: Atomic Structure

Explanation:

Cations must be positively charged so O^2- and F^- are eliminated straight away.

2024p1 q1 explain

Both Na⁺ and Mg²⁺ have the same number of electrons as neon atom (10 electrons).

We calculate the neutron numbers for both Na⁺ and Mg²⁺ to determine that the proton number and neutron number for Mg²⁺ are the same.

Question 2

2024p1 q2

Answer: D

Topic: Atomic Structure

Explanation:

Statement 1 is false - in a longer covalent bond the bond pair of electrons are further away from the nuclei, attraction between nuclei and shared pair of electrons are weaker hence bond energy is lower.

2024p1 q2 explain 1

Statement 2 is false - effective nuclear charge not nuclear charge will affect overall attraction between nucleus and valence electrons and hence bond energy. For instance for hydrogen halides, down the group nuclear charge for halogen increases but bond energy for H-X decreases.

2024p1 q2 explain 2

Statement 3 is true - attraction between shared electron pair and nuclei of bonded atoms is the definition of covalent bond hence stronger attraction means higher bond energy.

Question 3

2024p1 q3

Answer: C

Topic: Intermolecular Forces

Explanation:

Statement 1 is false - H₂S is more polar so should have stronger pd-pd attraction than H₂Se. Its lower boiling point is due to its smaller electron cloud size, polarisability and weaker id-id attraction.

Statement 2 is true - H₂O is smaller in size, electron cloud less polarisable hence temporary dipole - induced dipole attraction is weaker than H₂Se. Note that id-id attraction is present in any species with electron cloud, even if dominant IMF is pd-pd or H-bond (in the case for H₂O).

Statement 3 is true - H₂O is more polar so its pd-pd attraction is stronger than H₂S. Note H-bond is a very strong type of pd-pd attraction.

Question 4

2024p1 q4

Answer: D

Topic: Chemical Bonding

Explanation:

We can use VSEPR theory to deduce the shape and bond angle based on the number of bond pairs and lone pairs attached to the central atoms.

2024p1 q4 explain

Ammonium N and alkyl C - 4 bp and 0 lp, shape tetrahedral, bond angle 109.5 deg.

Acid C - 3 bp and 0 lp, shape trigonal planar, bond angle 120 deg.

Question 5

2024p1 q5

Answer: B

Topic: Atomic Structure

Explanation:

We consider the electron in box diagram of valence shell (n=3) for Na to Ar and count the number of unpaired electrons.

2024p1 q5 explain

Question 6

2024p1 q6

Answer: B

Topic: Mole Concept

Explanation:

For each of the compounds, we use the mass analysis to determine its formula and oxidation state of Si, P or S. Their highest oxidation state should be +4, +5 and +6 respectively.

2024p1 q6 explain

Question 7

2024p1 q7

Answer: A

Topic: Mole Concept

Explanation:

Relative atomic mass is the sum of isotopic mass*abundance divided by total abundance.

2024p1 q7 explain

Note that the total relative abundance is 102 and not the usual total percentage abundance of 100.

Question 8

2024p1 q8

Answer: D

Topic: Chemical Bonding

Explanation:

2024p1 q8 explain

To get the smallest magnitude for lattice energy, we want charge of ion to be smaller and size to be larger. Hence potassium peroxide.

Question 9

2024p1 q9

Answer: C

Topic: Kinetics

Explanation:

2024p1 q9 explain

24 hours has passed from 0.016 mol dm^-3 to 0.002 mol dm^-3 which is 3 half lifes. Hence each half life is 8 hours and time taken to decrease from 0.016 mol dm^-3 to 0.001 mol dm^-3 is 4 half lifes which takes 32 hours.

Question 10

2024p1 q10

Answer: C

Topic: Kinetics

Explanation:

Graph of [P] against time has constant half-life hence first order with respect to P.

2024p1 q10 explain 1

Comparing initial rates for the 2 experiments, [Q] increases by 2.4 times and initial rate increases by 5.76 times hence second order with respect to Q.

2024p1 q10 explain 2