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.

Triiodomethane or Iodoform Test

In this video created by Chemistry Guru, Singapore's leading JC Chemistry tuition centre, we want to discuss the triiodomethane test or iodoform test.

The reagents and conditions to administer the test is I₂ in NaOH(aq), warm.

The observation for a positive test is the formation of a yellow precipitate.

triiodomethane test reagents conditions observation

This test is used to identify certain types of alcohols and carbonyl compounds which contain these specific structures:

triiodomethane test structures that give positive test

If we study the 2 structures closely the common groups that are required are:

1. Methyl CH₃ group (yellow)
2. Carbon that carrys an oxygen, either an alcohol carbon CH(OH) or a carbonyl carbon C=O (blue)
3. Hydrogen or alkyl group (green)

triiodomethane test important parts of structure

On reaction with iodine in alkaline conditions, the methyl group will be converted to triiodomethane or iodoform which gives us the observation of yellow precipitate.

The carbon which carries the oxygen will be converted to salt of carboxylic acid or conjugate base of carboxylic acid, H/R-COO^-

triiodomethane test deduce products

Students will need to identify compounds which have the required structures to give a positive triiodomethane test.

Here are 3 examples for students to try out. Which of these compounds will give a positive triiodomethane test?

triiodomethane test examples

To find out the answers, check out this video now!

Topic: Alcohols, Organic Chemistry, A Level Chemistry, Singapore

Back to other previous Organic Chemistry Video Lessons.

Found this A Level Chemistry video useful?

This free chemistry video lesson is brought to you by Chemistry Guru, Singapore's reputable A Level Chemistry tuition centre since 2010.

Please like this video and share it with your friends!

Join my 18,000 subscribers on my YouTube Channel for new A Level Chemistry video lessons every week.

Check out other A Level Chemistry Video Lessons here!

Need an experienced tutor to make Chemistry simpler for you?

Do consider signing up for my JC Chemistry Tuition classes at Bishan or online chemistry classes!

Menu

Classes

Info

Resources

Videos

Paper 1

Triiodomethane or Iodoform Test