O Level Pure Chemistry & IP Chemistry Tuition by 10 Year Series Book Author

O Level Chemistry Question: Organic Chemistry / Alkene

Halo,

Came across the following question with my student today and thought you will be interested to give it a try:

Question:

Which statement is true for both propene and polypropene?
A) They have identical empirical formulae
B) They are insoluble in organic solvents
C) They have identical molecular formulae
D) They decolourise liquid bromine solution rapidly

Come on O Level students, give it a shot.I understand that lots of you are checking out on this blog. The best way to learn is to Just Do It (like NIKE)! Nothing to be shy about, just share your answer. It is alright if you got it wrong. Failure is the mother of success, still rmbr that?

PS: Thank you “C” for letting me this chance to share the above question.

Cheers
Sean
SimpleChemConcepts

Qn answered and explained under comments

O Level Chemistry Question: Chemical Bonding / Organic Chemistry

Hey students,

Try this O Level Chemistry questions on Bonding and Organic Chemistry.

Question:
The number of shared pairs electrons in a molecule of methanol is:
A) 3
B) 4
C) 5
D) 6

Show me your reasoning. You can leave your suggested answers in the “Comments” section below.

Rgds,
Sean
SimpleChemConcepts

Qn answered and explained under comments

O Level Chemistry Question: Redox Reaction

How about another O Level Chemistry Question on Redox Reactions as a food for thoughts over the weekend…

Question:

Which of the following conversions is a redox reaction (involves oxidation/reduction)?

A)H+ => H20
B)NO2 => NO3^-
C)SO2 => SO3^2-
D)SO3 => SO4^2-

Enjoy and take care.

Rgds,
Sean, Master Trainer @
SimpleChemConcept

O Level Chemistry Question: Electrolysis / Mole Concepts / Mole Calculations

Hey student,

Here is another one for you to think about. Yup. O Level Preliminary Chemistry question. Think about it and let me know.

Question:
A certain quantity of electricity liberates 9g of aluminiun. The volume of oxygen liberated at r.t.p from dilute sulphuric acid by the same quantity of electricity is:

A)6 dm^3
B)8 dm^3
C)12 dm^3
D)24 dm^3

Happy trying. Rmbr: Best thing is to write it down and play around with the equations. You will see the light in the tunnel….

Sean
Master Trainer @
SimpleChemConcepts

Qn answered and explained under comments

O Level Chemistry Question: Chemical Bonding & Structural Properties

Q) Since HCL has strong covalent bonds, why is it that they dissociate easily into H+ ions and Cl- ions when put in water?

Answers:

In GCE O Level education, this question is usually not posed. In Junior Collleges, detailed explanation will be given in general chemistry classes.

Suggested Answer:

The hydrogen chloride molecule HCl is a simple diatomic molecule consisting of a hydrogen atom H and a chlorine atom Cl connected with a covalent single bond. Since the chlorine atom is much more electronegative than the hydrogen atom, the covalent bond between the atoms is quite polar. Consequently the molecule has a large dipole moment with a negative partial charge ?- at the chlorine atom and a positive partial charge ?+ at the hydrogen atom. In part due to its high polarity, HCl is very soluble in water (and in other polar solvents).
Upon contact with water, it immediately ionizes, forming hydronium cations H3O+ and chloride anions Cl- through a reversible chemical reaction with the water:
HCl + H2O –> H3O+ + Cl?

The resulting solution is called hydrochloric acid and is a strong acid.

To Your Academic Success in Chemistry,
Sean Chua
Master Trainer @ SimpleChemConcepts.com

O Level Chemistry: How to gain most?

first of all, we would love to thanks all those who have posted your comments, shared your thoughts, asked your questions 🙂

Keep them coming! we welcome all! Since O Level is coming by in 25 days time, we would love to continue to see this blog active. btw, did i mention that there are on average 100 of you viewing this blog daily? not a huge number but both me and sean are happy that there are people who visit this blog. and we will continue to provide you with tips to do well.

this applies to students that are taking other educational examination system such as ICGSE, IB and IP students.

well, to ensure that you gain the most of out this, you yourself must participate! yeah participate is the key! ask all sorts of qns, answer qns the way u think is correct, just do it anyway! it is through participation that we can truly experience and learn at the maximum potential.

so when there are qns, have a pen and paper and work things out! see if your concepts and understanding are firm and clear.

keep the fire burning!

PS: Even if you have regular Chemistry Tuition or Chemistry Tutor, we welcome you to send us your questions. Cos we believe it is our duty to do so (with the resources we are able to find)

Cheers!
Sean Chua
Master Trainer