How to answer Section 2 questions

Section 2 is worth 80 marks: restricted and extended response questions, many set around an experiment or a set of data. The command word and the marks tell you how much to write.

Marks	80
Questions	Restricted and extended response
Includes	Two open-ended questions, 3 marks each
Content	All four areas

Answer to the command word

State or name: a short, exact answer, often a word or a formula.
Describe: what happens or what you would do, step by step.
Explain: the point and the reason for it, using because, so or which means.
Calculate: the working, the answer and its unit, to the significant figures the data justify.

Calculations

Write the balanced equation, convert to moles, use the mole ratio, then convert back. Change cm³ to litres before you use a concentration in mol l⁻¹. Give the unit, and do not quote far more figures than the data were given to.

Try 2 questions

Question 1

Rf values of four dyes
Dye	Rf value
P	0.36
Q	0.45
R	0.56
S	0.80

A food colouring is spotted on a start line drawn 1.5 cm above the bottom edge of a chromatography paper. After the run, its single spot is 4.2 cm above the bottom edge and the solvent front is 7.5 cm above the bottom edge. The table gives Rf values of four dyes in the same solvent. Which dye is the colouring most likely to be?

Question 2

What is the systematic name of (CH₃)₂CHCH₂COOH?

Next step

Take the free test Start the chemical analysis lesson

Questions people ask

How are written answers read here?

Mia reads each written answer against its mark points and says which points it shows and what to add next. She never shows a mark or writes the answer for you.

Do I need to show working in calculations?

Yes. Write each step so a marker can follow it, and finish with the value and its unit.