Barium sulfate is an insoluble salt used as a radiocontrast agent. It is produced by the reaction between barium chloride solution and sodium sulfate solution:
BaCl2(aq)+Na2SO4(aq)→BaSO4(s)+2NaCl(aq)\text{BaCl}_2\text{(aq)} + \text{Na}_2\text{SO}_4\text{(aq)} \rightarrow \text{BaSO}_4\text{(s)} + 2\text{NaCl(aq)}BaCl2(aq)+Na2SO4(aq)→BaSO4(s)+2NaCl(aq)
A student investigated the law of conservation of mass using the following method:
The table below shows the student's results:
| Mass before mixing (g) | Mass after mixing (g) | |
|---|---|---|
| Beaker A and contents | 85.34 | 120.45 |
| Beaker B and contents | 80.25 | 45.14 |
Explain how the results demonstrate the law of conservation of mass. You must use data from the table in your answer.
Calculate the percentage atom economy for the production of barium sulfate (BaSO4\text{BaSO}_4BaSO4) in this reaction. Give your answer to 3 significant figures.
Relative formula masses (MrM_{\text{r}}Mr): BaCl2=208\text{BaCl}_2 = 208BaCl2=208, Na2SO4=142\text{Na}_2\text{SO}_4 = 142Na2SO4=142, BaSO4=233\text{BaSO}_4 = 233BaSO4=233, NaCl=58.5\text{NaCl} = 58.5NaCl=58.5
Practise AQA GCSE Chemistry Yield and atom economy of chemical reactions (chemistry only) with exam-style questions for Foundation and Higher tier. 32 questions covering Percentage yield and Atom economy, matched to the AQA GCSE Chemistry (8462) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.