When 650 mg of barium is added to 450 cm3 of water at 21 ∘C21\text{ }^\circ\text{C}21 ∘C under a pressure of 102 kPa, a reaction occurs producing a gas.
Write a balanced molecular equation for the reaction that occurs.
Calculate the volume, in cm3\text{cm}^3cm3, of the gas formed. (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, relative atomic mass Ar(Ba)=137.3A_r(\text{Ba}) = 137.3Ar(Ba)=137.3)
Calculate the concentration, in mol dm−3\text{mol dm}^{-3}mol dm−3, of barium ions in the resulting solution. (Assume that the volume of the solution remains 450 cm3).
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.