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.

Calculate pH of Weak Acid

In this JC2 webinar we want to learn how to calculate the pH of a weak acid.

Let Chemistry Guru, Singapore's renowned JC Chemistry tuition centre, guide you through this question.

We know that this acid is weak since its acid dissociation constant K_a is given.

Note that strong acids are fully dissociated hence do not have K_a values.

We can write down the dissociation of the acid via the ICE table.

calculate weak acid pH ICE table

ICE stands for Initial, Change and Equilibrium.

Since the degree of dissociation is not known, we can let it be x.

Hence we can determine the equilibrium concentrations of CH₃COOH, CH₃COO^- and H⁺ in terms of x.

Next we can substitute these values into the K_a expression.

calculate weak acid pH Ka expression

Since K_a is known, we now have an equation in terms of x, and we can solve for it.

However the equation is quadratic so we have to do an approximation to simplify the calculation.

Note that for A Level Chemistry Syllabus, solving for quadratic equations is not required.

The approximation is pretty simple. Since the degree of dissociation is small, we assume the concentration of the acid at equilibrium is equal to its initial concentration.

calculate weak acid pH approximation