QUESTION 23 (4 marks)
Ibuprofen is manufactured using two different processes.
Process | Number of reagents used | Reagents | Ibuprofen | Waste products | |||
Atoms | Mr | Atoms | Mr | Atoms | Mr | ||
1 | 7 | C20H42NO10ClNa | 514.5 | C13H18O2 | 206.0 | C7H24NO8ClNa | 308.5 |
2 | 4 | C15H22O4 | 266.0 | C13H18O2 | 206.0 | C2H4O2 | 60.0 |
Calculate the atom economy for each process and draw conclusions about the economic and environmental impact of each process.
QCAA guide · typeset solution
QCAA sample response and mark allocation
23 | Process 2 has 37.4% better atom economy than process 1 Economic impact: Process 2 has a better atom economy than process 1 (fewer reagents are required). Environmental impact: Process 2 is greener than process 1 because fewer waste products (atoms) are produced. | • calculates atom economy for - Process 1 as 40% [1 mark] - Process 2 as 77% [1 mark] • concludes process 2 is - cheaper as fewer reagent atoms are required [1 mark] - greener as fewer waste atoms are produced [1 mark] |
QCAA sample response and marking criteria reproduced from the official guide.
Compare your working with the guide above.