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.

2023 A Level H2 Chemistry Paper 1 Solutions - Questions 21 to 30

Question 21

2023p1 q21

Answer: A

Topic: Halogenoalkane

Explanation:

The carbon bonded to bromine in 3-bromo-3-methylhexane is chiral and tertiary. The product mixture of 2 isomeric alcohols indicate mechanism is via S_N1 to form an equimolar mixture of 2 optical isomers ie racemic mixture.

Therefore only statement A is consistent with S_N1 mechanism.

2023p1 q21 explain

Question 22

2023p1 q22

Answer: B

Topic: Halogenoalkane

Explanation:

Comparing hydrolysis reaction, propanoyl chloride is most reactive since acid carbon is bonded to 2 electronegative elements hence acid carbon is most positive and attractive to nucleophiles.

Chlorobenzene is the least reactive as lone pair on Cl is delocalised into pi system of benzene hence C-Cl bond resonance stabilised and unreactive.

2023p1 q22 explain

Question 23

2023p1 q23

Answer: A

Topic: Alkene and Mole Concept

Explanation:

From the balanced equation for combustion of hydrocarbon C_xH_y, we can write out the mole ratio and volume ratio of C_xH_y, O₂ and CO₂.

By comparing mole ratio to volume ratio, we can solve for x = 5 and y = 10. Hence molecular formula for hydrocarbon is C₅H₁₀.

C₅H₁₀ can be cycloalkane such as unbranched cyclopentane or branched methylcyclobutane. It can also be alkene such as pent-1-ene or pent-2-ene. So all statements are correct.

2023p1 q23 explain

Question 24

2023p1 q24

Answer: B

Topic: Organic Chem Application

Explanation:

To deduce how heptane can be converted to methylbenzene, we have to draw a closed loop of 6 carbons with a methyl group attached to carbon-1.

Hence in order for the C₈H₁₈ isomer to form 1,4-dimethylbenzene, we have to draw a closed loop of 6 carbons with a methyl group attached to carbon-1 and another methyl group attached to carbon-4.

For each of these possible isomers we have to do a bit of trial and error to deduce that isomers 1 and 2 are correct.

2023p1 q24 explain

Question 25

2023p1 q25

Answer: D

Topic: Carboxylic Acid and Derivatives

Explanation:

The reaction is between acid chloride and phenol to form ester functional group. Hence ethanoyl chloride reacts with 4-methylphenol to form 4-methylphenylethanoate.

2023p1 q25 explain

Question 26

2023p1 q26

Answer: B

Topic: Carboxylic Acid and Derivatives

Explanation:

Functional groups such as carboxylic acids and phenols are more acidic than water and will dissociate in heavy water D₂O to form HD₂O⁺ and conjugate base. The reverse process is also possible where conjugate base accepts deuterium cation D⁺ from HD₂O⁺ hence hydrogen is replaced by deuterium.

2023p1 q26 explain

Question 27

2023p1 q27

Answer: D

Topic: Nitrogen Compounds and Proteins

Explanation:

The repeat unit of primary structure of protein is -NHCHRCO- with positions:

1 - amine N
2 - carbon with R group
3 - acid C

Hence a tripeptide will also have the same repeat unit thrice.

Only structures 2 and 3 follow this repeat unit and are tripeptides.

2023p1 q27 explain

Question 28

2023p1 q28

Answer: A

Topic: Electrochemistry

Explanation:

Statement 1 is correct since only water is formed from hydrogen-oxygen fuel cell.

Statement 2 is correct.

Statement 3 is correct as hydrogen is oxidised to H⁺ hence electrons are released.

2023p1 q28 explain

Question 29

2023p1 q29

Answer: B

Topic: Electrochemistry

Explanation:

Statement 1 is correct. When standard hydrogen electrode is attached to a half-cell with negative E, SHE will have more positive E and undergoes reduction to form H₂ gas.

Statement 2 is wrong since standard redox potential for SHE is 0.00V.

Statement 3 is wrong as 1.00 moldm^-3 H₂SO₄ will give 2.00 moldm^-3 H⁺ which is not standard conditions of 1.00 moldm^-3.

2023p1 q29 explain