Monitoring chemical reactions

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Question 34
Medium

Potassium nitrate, KNO3\text{KNO}_3KNO3​, is a highly valuable potassium- and nitrogen-based compound used extensively in synthetic fertilisers.

a.

Explain why potassium-based fertilisers are essential in the modern agricultural industry.

[2]
b.

Potassium nitrate is manufactured on an industrial scale by reacting potassium hydroxide with nitric acid:

KOH+HNO3→KNO3+H2O\text{KOH} + \text{HNO}_3 \rightarrow \text{KNO}_3 + \text{H}_2\text{O}KOH+HNO3​→KNO3​+H2​O

Calculate the mass of potassium nitrate that could be produced from 11.2 tonnes11.2\text{ tonnes}11.2 tonnes of potassium hydroxide.

Relative atomic masses (ArA_rAr​): H=1.0\text{H} = 1.0H=1.0, N=14.0\text{N} = 14.0N=14.0, O=16.0\text{O} = 16.0O=16.0, K=39.0\text{K} = 39.0K=39.0.

[3]
c.

A chemist synthesises a sample of potassium nitrate in the laboratory.

Based on her reactant measurements, she calculates a theoretical yield of 15.0 g15.0\text{ g}15.0 g of potassium nitrate.

Her experimental percentage yield is 84%84\%84%.

Calculate the actual mass of potassium nitrate that she successfully isolates.

[2]

Monitoring chemical reactions Questions

  1. GCSE
  2. /Chemistry
  3. /Monitoring chemical reactions