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.

How to Draw Born Haber Cycle of Ionic Compounds - Energetics

In this video we want to learn how to draw the Born Haber Cycle of ionic compounds using CaCl₂ as an example.

We usually use the energy level diagram to present the Born Haber Cycle, which can be broken down into 4 steps.

1. Formation

Formation involves the reaction from elements in the standard state to ionic compound. Usually enthalpy change of formation for ionic compounds is exothermic as ionic compounds are stable.

We can draw this close to the bottom of the energy level diagram as the rest of the terms would be endothermic hence pointing upwards.

Born Haber Cycle formation

2. Atomisation

Atomisation involves forming gaseous atoms for both calcium metal and chlorine gas. Both terms are endothermic as energy is required to break all bonds in the elements to form gaseous atoms.

For Ca we will be given the enthalpy change of atomisation of metal.

For Cl₂ usually we use bond energy of Cl-Cl bond which can be found in the Data Booklet.

Born Haber Cycle atomisation

3. Ionisation

Ionisation involves removing the electrons from Ca (ionisation energy) and adding electrons to Cl (electron affinity).

Removing 2 electrons from Ca to form Ca²⁺ will be the first and second ionisation energies of Ca which can be found in the Data Booklet. Ionisation energy is endothermic as energy is required to overcome attraction between nucleus and valence electron.

Adding electron to Cl to form Cl^- will be the first electron affinity of Cl. First electron affinity is exothermic as energy is released from attraction formed between nucleus and added electron.

Born Haber Cycle ionisation

4. Lattice Energy

The last step involves lattice energy which is the forming of ionic compound from its constituent gaseous ions.

Since strong ionic bonds are formed, lattice energy is highly exothermic.

Born Haber Cycle lattice energy

Hess' Law

We can use the follow expression to work out the relationship of all the terms in the Born Haber cycle. This expression is valid for all ionic compounds.

Born Haber Cycle hess law