Metals such as magnesium and zinc react with dilute sulfuric acid to give hydrog
ID: 765534 • Letter: M
Question
Metals such as magnesium and zinc react with dilute sulfuric acid to give hydrogen, according to the equation: M (s) + H2SO4 (aq) -------> MSO4 (aq) + H2 (g) (i think u need to balance) When 5.00 g of a mixture of powdered magnesium and zinc were dissolved in diluted sulfuric acid, 0.284 g of hydrogen gas was collected. What was the composition of the mixture of Mg and Zn expressed as percent by mass? If the volume of acid used was 100 mL, what were the final molar concentrations of MgSO4 and ZnSO4?Explanation / Answer
let the mass of the zince be x grams. mass of magnesium =5-x grams. well you have not mentioned the molarity of the acid solution. so i am taking it to be m. so , moles of H2 liberated=0.284/2 =0.142moles, so, x/65 + (5-x)/24 = 0.142 or x = 2.524 so mass of zinc present=2.254 grams mass of magnesium present=2.746 grams. so, moles of ZnSO4 formed=2.254/65 =0.035 moles of MgSO4 formed=2.746/24 =0.1144 molarity of ZnSO4=0.35 molarity of MgSO4=1.14