In an investigation into the enthalpy of combustion of different alcohols, a student used a copper calorimeter to measure the energy released per gram of fuel burned. Due to heat losses to the laboratory surroundings, the experimental energy values obtained were lower than standard values. The student's recorded data is shown in the table below.
| Alcohol | Formula of one molecule of the alcohol | Experimental energy released in kJ/g\text{kJ/g}kJ/g |
|---|---|---|
| Methanol | CH3OH\text{CH}_3\text{OH}CH3OH | 19.819.819.8 |
| Ethanol | C2H5OH\text{C}_2\text{H}_5\text{OH}C2H5OH | 26.426.426.4 |
| Propanol | C3H7OH\text{C}_3\text{H}_7\text{OH}C3H7OH | 29.129.129.1 |
| Butanol | C4H9OH\text{C}_4\text{H}_9\text{OH}C4H9OH | 31.831.831.8 |
| Pentanol | C5H11OH\text{C}_5\text{H}_{11}\text{OH}C5H11OH | 33.533.533.5 |
| Octanol | C8H17OH\text{C}_8\text{H}_{17}\text{OH}C8H17OH | 36.236.236.2 |
Calculate the mass of methanol that must be burned to release the same quantity of heat energy as is released by burning 1.85 g1.85\text{ g}1.85 g of butanol under these experimental conditions.
Give your answer to 3 significant figures.
12 exam-style questions on AQA GCSE Chemistry 7.2 Reactions of alkenes and alcohols, covering 7.2.1 Structure and formulae of alkenes, 7.2.2 Reactions of alkenes, 7.2.3 Alcohols, and 7.2.4 Carboxylic acids. Each one has a worked solution and a mark scheme showing where the marks go.