Maths 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
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)
Take extra care when converting between units.
This page contains AQA material which is reproduced by permission of AQA.
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Sample question 1 - Foundation
Question
Calcium carbonate reacts with nitric acid to produce calcium nitrate.
Calculate the relative formula mass (Mr) of calcium nitrate, Ca(NO3)2.
Relative atomic masses (Ar): N = 14; O = 16; Ca = 40 [2 marks]
40 + 2(14 + (3 脳 16)) [1]
= 164 [1]
Sample question 2 - Foundation
Question
Aluminium reacts with sulfuric acid (H2SO4) to produce aluminium sulfate, Al2(SO4)3 and hydrogen (H2).
Complete and balance the equation for this reaction. [2 marks]
___Al + ______ 鈫 ______ + _____
2Al + 3H2SO4 鈫 Al2(SO4)3 + 3H2
Correct formulae is rewarded with one mark.
One mark rewarded for correct balancing.
Sample question 3 - Higher
Question
At 20掳C, 190 g of ammonium nitrate (NH4NO3) dissolves in 100 cm3 of water.
Calculate the amount of ammonium nitrate (in moles) that dissolves in 1 dm3 of water at 20掳C. [3 marks]
Relative atomic masses (Ar): H = 1; N = 14; O = 16
Relative formula mass of NH4NO3 = 14 + (4 脳 1) + 14 + (3 脳 16) = 80 [1]
Mass of ammonium nitrate in 1 dm3 at 20掳C = 190 脳 10 = 1,900 g [1]
Number of moles of ammonium nitrate in 1,900 g = 1,900 梅 80 = 23.75 mol [1]
Sample question 4 - Higher
Question
Calculate the number of molecules in 14 g of carbon dioxide.
Give your answer in standard form.
Relative atomic masses (Ar): C = 12; O = 16 [4 marks]
1 mole of carbon dioxide has a mass of = 12 + (16 脳 2) = 44 g [1]
14 g is 14/44 = 0.32 mol [1]
1 mole has 6.02 脳 1023 molecules [1]
So 14 g has (6.02 脳 1023 脳 0.32)
= 1.93 脳 1023 molecules [1]