A student carries out a titration to find the concentration of a lithium hydroxide solution using dilute sulfuric acid.
The table below shows the student's results:
| Titration number | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| Volume of acid (cm3\text{cm}^3cm3) | 24.8 | 23.1 | 23.3 | 23.2 |
The student decides that the best value for the mean (average) volume of acid is 23.2 cm323.2\text{ cm}^323.2 cm3.
Show how she calculated this value.
The chemical equation for this reaction is:
H2SO4+2LiOH→Li2SO4+2H2O H_2SO_4 + 2LiOH \rightarrow Li_2SO_4 + 2H_2O H2SO4+2LiOH→Li2SO4+2H2OThe table below shows the relative formula masses (MrM_rMr) for each substance:
| Substance | Relative formula mass, MrM_rMr |
|---|---|
| H2SO4H_2SO_4H2SO4 | 98 |
| LiOHLiOHLiOH | 24 |
| Li2SO4Li_2SO_4Li2SO4 | 110 |
| H2OH_2OH2O | 18 |
Water is a waste product in this reaction, while lithium sulfate is the desired product.
Calculate the atom economy for this reaction to produce lithium sulfate. Give your answer to 1 decimal place.
81 exam-style questions on OCR GCSE Chemistry Improving processes and products. Each one has a worked solution and a mark scheme showing where the marks go.