Lithium hydroxide (LiOH\text{LiOH}LiOH) and lithium peroxide (Li2O2\text{Li}_2\text{O}_2Li2O2) have been used in closed life-support environments, such as spacecraft cabins, to scrub carbon dioxide from the air.
The equations for their reactions with carbon dioxide are:
2LiOH+CO2→Li2CO3+H2O 2\text{LiOH} + \text{CO}_2 \rightarrow \text{Li}_2\text{CO}_3 + \text{H}_2\text{O} 2LiOH+CO2→Li2CO3+H2O 2Li2O2+2CO2→2Li2CO3+O2 2\text{Li}_2\text{O}_2 + 2\text{CO}_2 \rightarrow 2\text{Li}_2\text{CO}_3 + \text{O}_2 2Li2O2+2CO2→2Li2CO3+O2Explain, with reference to these equations, two advantages of using lithium peroxide, rather than lithium hydroxide, to remove carbon dioxide from the air in a spacecraft.
Calculate the mass of lithium hydroxide needed to react with 198 g198\text{ g}198 g of carbon dioxide.
[Mr of LiOH=24][M_r \text{ of LiOH} = 24][Mr of LiOH=24]
Calculate the volume of carbon dioxide, at room temperature and pressure (rtp), removed by 115 g115\text{ g}115 g of lithium peroxide.
[Mr of Li2O2=46][M_r \text{ of Li}_2\text{O}_2 = 46][Mr of Li2O2=46]
Assume that one mole of gas has a volume of 24 000 cm324\,000\text{ cm}^324000 cm3 at rtp.
80 exam-style questions on Edexcel IGCSE Chemistry Chemical formulae, equations and calculations. Each one has a worked solution and a mark scheme showing where the marks go.