An industrial chemist reacts 45.0 g45.0\text{ g}45.0 g of ethene, C2H4\text{C}_2\text{H}_4C2H4, with excess steam, H2O\text{H}_2\text{O}H2O, to make ethanol, C2H5OH\text{C}_2\text{H}_5\text{OH}C2H5OH.
The equation shows this reaction.
C2H4+H2O→C2H5OH \text{C}_2\text{H}_4 + \text{H}_2\text{O} \rightarrow \text{C}_2\text{H}_5\text{OH} C2H4+H2O→C2H5OHCalculate the theoretical yield of ethanol, C2H5OH\text{C}_2\text{H}_5\text{OH}C2H5OH.
Give your answer to 3 significant figures.
Relative atomic mass (ArA_rAr): H=1.0C=12.0O=16.0\text{H} = 1.0 \quad \text{C} = 12.0 \quad \text{O} = 16.0H=1.0C=12.0O=16.0
Theoretical yield = ______ g\text{g}g
The atom economy for the reaction between ethene and steam is 100%.
C2H4+H2O→C2H5OH \text{C}_2\text{H}_4 + \text{H}_2\text{O} \rightarrow \text{C}_2\text{H}_5\text{OH} C2H4+H2O→C2H5OHUse the balanced symbol equation to explain why the atom economy is 100%.
In another reaction, the chemist makes 51.0 g51.0\text{ g}51.0 g of ethanol.
They predicted that they should have made 75.0 g75.0\text{ g}75.0 g.
Calculate their percentage yield.
Give your answer to 2 significant figures.
Percentage yield = ______ %
91 exam-style questions on OCR GCSE Chemistry Monitoring chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.