A student added 1430 mg1430\text{ mg}1430 mg of hydrated sodium carbonate (Na2CO3⋅xH2O\text{Na}_2\text{CO}_3 \cdot x\text{H}_2\text{O}Na2CO3⋅xH2O) to 100 cm3100\text{ cm}^3100 cm3 of 0.200 mol dm−30.200\text{ mol dm}^{-3}0.200 mol dm−3 hydrochloric acid in a beaker and stirred the mixture.
After the reaction was complete, the resulting solution was transferred to a volumetric flask, made up to 250 cm3250\text{ cm}^3250 cm3 with deionised water and mixed thoroughly.
Several 25.0 cm325.0\text{ cm}^325.0 cm3 portions of the resulting solution were titrated with 0.0500 mol dm−30.0500\text{ mol dm}^{-3}0.0500 mol dm−3 aqueous sodium hydroxide. The mean titre was 20.00 cm320.00\text{ cm}^320.00 cm3 of aqueous sodium hydroxide.
Calculate the value of xxx in Na2CO3⋅xH2O\text{Na}_2\text{CO}_3 \cdot x\text{H}_2\text{O}Na2CO3⋅xH2O.
Show your working.
Give your answer as an integer.
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.