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.

A Level Chemistry 2017 Paper 1 Question 20 Solution - Exclusive

In this exclusive video we want to discuss the suggested solution for A Levels Chemistry (H2 Chemistry) 2017 Paper 1 Question 20.

Let Chemistry Guru, Singapore's top JC Chemistry tuition centre, guide you through this question:

2017 H2 Chemistry Paper 1 Qn 20 question

The topic tested in this question is on the acidity of carboxylic acids.

From the pK_a values we know that the acidity of the acids are in the following order:

(least acidic) CH₃COOH < ClCH₂COOH < FCH₂COOH (most acidic)

Acidity of an organic compound is related to the stablity of its conjugate base.

The more stable the conjugate base, the more likely the dissociation of the weak acid to form the conjugate base, the more H⁺ is released hence the more acidic the weak acid.

For chloroethanoic acid, the electronegative Cl group is electron withdrawing which helps disperse the negative charge on oxygen of the carboxylate anion.

The conjugate base is more stable therefore chloroethanoic acid is more acidic and has a smaller pK_a value than ethanoic acid.

2017 H2 Chemistry Paper 1 Qn 20 chloroethanoic acid

For fluoroethanoic acid, F is more electronegative than Cl which makes it a more electron withdrawing group.

The conjugate base will be stabilised to the greatest extent therefore fluoroethanoic acid is the most acidic and has the smallest pK_a value.

2017 H2 Chemistry Paper 1 Qn 20 fluoroethanoic acid

Once we have the concept sorted out we can go through the 3 statements and decide that only statement 1 is valid. Hence the answer to this question is option C.

2017 H2 Chemistry Paper 1 Qn 20 compare statements and solution