A sample of isomer Y\text{Y}Y (C5H8O2\text{C}_5\text{H}_8\text{O}_2C5H8O2) was mixed with an excess of oxygen and the mixture ignited. After cooling to the original temperature, the total volume of gas remaining was 365 cm3365\text{ cm}^3365 cm3.
When this gas mixture was passed through aqueous sodium hydroxide, the carbon dioxide reacted and the volume of gas decreased to 125 cm3125\text{ cm}^3125 cm3.
Both gas volumes were measured at 20 ∘C20\text{ }^\circ\text{C}20 ∘C and 102 kPa102\text{ kPa}102 kPa.
Write an equation for the complete combustion of Y\text{Y}Y in an excess of oxygen and calculate the mass, in mg, of Y\text{Y}Y used.
The gas constant R=8.31 J K−1 mol−1R = 8.31\text{ J K}^{-1}\text{ mol}^{-1}R=8.31 J K−1 mol−1.
79 exam-style questions on AQA A Level Chemistry Amount of substance, covering Relative atomic mass and relative molecular mass, The mole and the Avogadro constant, The ideal gas equation, Empirical and molecular formula, and Balanced equations and associated calculations. Each one has a worked solution and a mark scheme showing where the marks go.