Syllabus and sample questions

Questions will generally be based on the syllabus of the GCE Ordinary Level. The committee strives to produce high-level questions and therefore, the questions may not carry the same style as the O levels examination. Some content knowledge is essential, but the focus of the questions is on analytical, reasoning and creative skills.

You may refer to the below past year questions provided by the scientific committee.

Round 1: Sample question

Download past year questions here.

Round 2: Sample question

 Watch the Lipid Extraction 1 video and answer the Questions below.

Question 1

Solution A comprises of three different compounds, namely ammonium hydroxide, n-Butyl alcohol, and ethyl alcohol. You are tasked to prepare solution A.

Calculate the volume of each reagent added to obtain 12.5 mL of solution A. [2m]

You are given the following information below:

i. Density: ammonium hydroxide [0.9 g/mL], n-Butyl Alcohol [0.8097 g/mL] and ethyl alcohol [0.789 g/mL]

ii. Molar Mass: ammonium hydroxide [35.05 g/mol], n-Butyl Alcohol [74.12 g/mol] and ethyl alcohol [46.07 g/mol]

iii. Number of moles: ammonium hydroxide [0.193 mol], n-Butyl Alcohol [0.038 mol] and ethyl alcohol [0.026 mol]

Question 2

Solution B comprises of two different compounds, namely Trisodium Phosphate and Sodium Acetate. You are tasked to prepare solution B.

Calculate the concentration (in mol/ L) of each reagent added to obtain 4000 mL of solution B in H2O. [2m]

You are given the following information below:

i. Mass: Trisodium Phosphate [200 g] and Sodium Acetate [150 g]

ii. Molar Mass: Trisodium Phosphate [163.94 g/mol] and Sodium Acetate [82.03 g/mol]

Question 3 (Open ended question)

What do you think could be the reasons for a deviation in the value from the Babcock method as compared to the manufacturer’s value? What are some of the experimental errors you might foresee in this experiment? [2m]