Tungsten is extracted from tungsten(VI) oxide using hydrogen gas. The balanced equation for the reaction is:
WO3+3H2→W+3H2O \text{WO}_3 + 3\text{H}_2 \rightarrow \text{W} + 3\text{H}_2\text{O} WO3+3H2→W+3H2OCalculate the atom economy for the production of tungsten in this reaction.
Give your answer to three significant figures.
(Relative formula masses: WO3=232\text{WO}_3 = 232WO3=232, H2=2\text{H}_2 = 2H2=2, W=184\text{W} = 184W=184, H2O=18\text{H}_2\text{O} = 18H2O=18)
157 exam-style questions on Edexcel GCSE Chemistry 6.2 Quantitative analysis, covering 6.2.1 Concentration in mol dm⁻³ and titration calculations, 6.2.2 Percentage yield and why actual yield falls short, 6.2.3 Atom economy of a reaction, 6.2.4 Choosing a reaction pathway, and 6.2.5 Molar volume of gases and Avogadro's law. Each one has a worked solution and a mark scheme showing where the marks go.