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.

How well do your students perform after attending your H2 Chemistry tuition classes?

Most of my students showed improvements by at least 3 grades and more than 80% have attained distinction for A Levels. The earlier the students join my classes, the more confident I am in improving their grades.

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.

2020 P1 Q28 - Determine Moles of O2 Released at Anode

Let Chemistry Guru, Singapore's top choice for JC Chemistry tuition, guide you through 2020 A Levels H2 Chemistry Paper 1 Question 28.

2020 p1 q28 question

We are required to determine the moles of oxygen gas released at the anode for electrolysis of dilute sulfuric acid.

Let's first consider the species that can be oxidised at the anode.

2020 p1 q28 species at anode

We have 2 species to consider, sulfate ions and water.

We need to choose the relevant half equations in the data booklet to compare E value.

Since oxidation occurs at anode, these 2 species must be found on the right hand side of the half equation.

2020 p1 q28 deduce water oxidised at anode

Comparing the following 2 half equations,

S₂O₈^2- + 2e ↔ 2SO₄^2- +2.01V
O₂ + 4H⁺ + 4e ↔ 2H₂O +1.23V

Water has the more negative E value, hence more likely oxidised at the anode.

Therefore water will be oxidised according to the following half equation:

2H₂O → O₂ + 4H⁺ + 4e

We can now calculate moles of oxygen gas via the following steps:
- calculate moles of electrons using Faraday's equations
- calculate mole of O₂ by comparing mole ratio of O₂ to electron

2020 p1 q28 calculate moles of O2