125 g of lithium metal reacts with 3.0 L of 2.5 mol/L sulfuric acid solution.
a)Calculate the mass of lithium remaining after the reaction is over.
b) Calculate the volume of hydrogen gas produced, if this reaction occurs at STP.
Reaction: 2Li + H2SO4 = Li2SO4 + H2
First seek theamount of substance for the lithium and sulfuric acid: n(Li) = 125/7 = 17.857 mol n(H2SO4) = 3 x 2.5 = 7.5 mol
Next seek the amount ofsubstance lithium remaining after the reaction is over: n(Li) = 17.857 - 15 = 2.857 remaining after the reaction is over.
Тhe amount of substance ofhydrogen will be: n(H2) = n(H2SO4) = 15 mol V(H2) = n(H2) x Vm(H2) V(H2) = 15 mol x 22.4 mol/l = 336 liters