Edexcel IAL Chemistry Ratios and Percentages

Practise Edexcel IAL Chemistry ratios, fractions and percentages through percentage composition, yield, error, volume fractions and mole-ratio calculations.

Exam points

Calculate percentage by mass from formulae or repeat units, checking every carbonyl, chlorine or OH contribution.
Use percentage yield or composition to scale masses, volumes and land area with unit conversions.
Derive mole ratios from percentage composition and relative atomic masses, then simplify to an empirical ratio.

[Maximum number: 1]

The reaction shown is at equilibrium. The forward reaction is endothermic.

\mathrm{C}(\mathrm{~s})+\mathrm{CO}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{CO}(\mathrm{~g})

At $680^{\circ} \mathrm{C}$ and $1 \mathrm{~atm}, 52.6 \%$ of the molecules in the gas mixture are carbon monoxide. What is the partial pressure of carbon dioxide, in atmospheres?

0.237

0.263

0.474

0.526

All question bank results loaded

B.0.2—Ratios, fractions and percentages question 1