A farmer wants to test the pH of soil samples. He researches information about different pH test kits.
Look at the information he finds.
pH of soil sample | ||||||
pH test kit | Price | pH2 | pH4 | pH7 | pH9 | pH14 |
A | £4.95 | Red | Yellow | Green | Blue | Purple |
B | £10.99 | Yellow | Yellow | Pink | Pink | Pink |
C | £11.50 | Pink | Orange | Yellow | Blue | Blue |
D | £2.99 | Colourless | Colourless | Colourless | Pink | Pink |
E | £12.75 | Red | Orange | Yellow | Yellow | Yellow |
[6]
Higher Only
Acidic soil can be neutralised by spreading magnesium carbonate, MgCO3, onto the soil.
The farmer uses 25.0 kg of magnesium carbonate.
Calculate the number of moles of magnesium carbonate the farmer uses.
(Ar: C = 12.0; Mg = 24.3; O = 16.0)
Give your answer to 3 significant figures.
Number of moles of magnesium carbonate = .......................................................... [3]
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