This question is about the extraction of metals.
Element X\text{X}X is extracted from its dioxide by reduction with carbon monoxide.
The equation for the reaction is:
XO2+2CO→X+2CO2 \text{XO}_2 + 2\text{CO} \rightarrow \text{X} + 2\text{CO}_2 XO2+2CO→X+2CO2The sum of the relative formula masses (MrM_rMr) of the reactants (XO2+2CO\text{XO}_2 + 2\text{CO}XO2+2CO) is 136.
Calculate the relative atomic mass (ArA_rAr) of X\text{X}X.
Relative atomic masses (ArA_rAr): C=12\text{C} = 12C=12, O=16\text{O} = 16O=16.
Identify element X\text{X}X using the periodic table.
53 exam-style questions on AQA GCSE Chemistry 3.1 Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations, covering 3.1.1 Conservation of mass and balanced chemical equations, 3.1.2 Relative formula mass, 3.1.3 Mass changes when a reactant or product is a gas, and 3.1.4 Chemical measurements. Each one has a worked solution and a mark scheme showing where the marks go.