The unbalanced equation for the reaction of acidified potassium manganate(VII) with hydrogen peroxide is shown below.
…MnO4−(aq)+…H2O2(aq)+…H+(aq)→…Mn2+(aq)+…O2(g)+…H2O(l) \dots \text{MnO}_4^-(\text{aq}) + \dots \text{H}_2\text{O}_2(\text{aq}) + \dots \text{H}^+(\text{aq}) \rightarrow \dots \text{Mn}^{2+}(\text{aq}) + \dots \text{O}_2(\text{g}) + \dots \text{H}_2\text{O(l)} …MnO4−(aq)+…H2O2(aq)+…H+(aq)→…Mn2+(aq)+…O2(g)+…H2O(l)Which numbers for H2O2(aq)\text{H}_2\text{O}_2(\text{aq})H2O2(aq) and H2O(l)\text{H}_2\text{O(l)}H2O(l) will balance the equation?
| H2O2(aq)\text{H}_2\text{O}_2(\text{aq})H2O2(aq) | H2O(l)\text{H}_2\text{O(l)}H2O(l) | |
|---|---|---|
| A | 5 | 8 |
| B | 5 | 4 |
| C | 2 | 8 |
| D | 3 | 4 |
555 and 888
555 and 444
222 and 888
333 and 444
199 exam-style questions on OCR A A Level Chemistry Atoms and reactions, covering Atomic structure and isotopes, Compounds, formulae and equations, Amount of substance, Acids, and Redox. Each one has a worked solution and a mark scheme showing where the marks go.