Understanding how to approach exam questions helps to boost exam performance. Question types will include multiple choice, structured, mathematical and practical questions.

Don't forget to take a ruler and scientific calculator into the exam.

Maths questions often start with the command word calculate. You need to use numbers given in the question to work out the answer.

When an answer to a maths question is marked:

- full marks are given for the right answer
- marks may be given for working, including substitution and rearrangement
- calculation errors carried forward are worked through to give credit for later working

Always show working in calculation questions. You can get marks for correct working, even if the answer is wrong.

Take extra care when converting between units.

Make sure you give answers to a suitable number of significant figures.

Maths questions might ask you to plot or complete a **graph** or **table**. When you draw a graph, make sure you:

- plot each point accurately
- draw a best fit straight line or curve, where appropriate

You may be given a grid with axes labelled and scales already given. Sometimes you may be given an empty grid for you to supply your own axes. When you do this:

- put the independent variable on the x-axis and the dependent variable on the y-axis
- choose even scales and make sure that the points cover at least half the given grid
- label the axes with their quantity and unit, eg time (s)

*These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.*

- Question
Calcium nitrate contains calcium ions and nitrate ions.

Calculate the relative formula mass of calcium nitrate, Ca(NO

_{3})_{2}.(relative atomic masses: Ca = 40, N = 14, O = 16)

**[2 marks]**40 + (2 × 14) + (6 x 16) [1]

= 164 [1]

- Question
Magnesium reacts with oxygen:

2Mg + O

_{2}→ 2MgOCalculate the maximum mass of magnesium oxide that can be formed from 4.8 g of magnesium.

(Relative atomic mass of Mg = 24; relative formula mass of MgO = 40)

**[2 marks]**24 g of Mg produces 40 g of MgO. [1]

so 4.8 g of Mg produces 40 × 4.8/24 = 8 g [1]

- Question
Calculate the mass of 0.25 mol of carbon dioxide, CO

_{2}.(relative atomic masses: C = 12, O = 16)

**[2 marks]**12 + (2 × 16) = 44 [1]

(mass of 1 mole = 44 g)

0.25 mol × 44 g/mol = 11 g [1]

- Question
50 cm

^{3}of potassium hydroxide solution of concentration 40 g/dm^{3}is needed for an experiment.Calculate the mass of potassium hydroxide that must be dissolved in water to make 50 cm

^{3}of solution of this concentration.**[2 marks]**Volume in dm

^{3}= 50 /1000 = 0.050 dm^{3}Mass = concentration × volume

Mass = 40 g/dm

^{3}× 0.050 dm^{3}[1]= 2 g [1]