Question
If 6.5g of zinc react with 5.0g of HCl which subance is the limiting reactant? How many gram of the reactant remaint unreacted? How many gram of hydrogen would be produced?
Answers
DrBob222
Zn + 2HCl ==> ZnCl2 + H2
mols Zn = 6.5/65.4 = 0.0994
moles HCl = 5.0/36.5 = 0.137
If all of the 0.0994 mols Zn react how much HCl will be required? That's 0.0994 x 2 = 0.199. You don't have much HCl; therefore, HCl is the limiting reagent (LR) and Zn is the excess regent (ER).
b) moles Zn required to react with all of the HCl = 0.137 x (1 mol Zn/2 mols HCl) = 0.137 x 1/2 = 0.0685. So you will have left 0.0994 - 0.0685 = ? moles Zn and grams Zn = moles Zn x atomic mass Zn = ?
c) moles H2 produced = 0.137 moles HCl x (1 mol H2/2 mols HCl) = 0.137 x (1/2) = 0.0685. Then grams H2 = moles H2 x molar mass H2 = ?
mols Zn = 6.5/65.4 = 0.0994
moles HCl = 5.0/36.5 = 0.137
If all of the 0.0994 mols Zn react how much HCl will be required? That's 0.0994 x 2 = 0.199. You don't have much HCl; therefore, HCl is the limiting reagent (LR) and Zn is the excess regent (ER).
b) moles Zn required to react with all of the HCl = 0.137 x (1 mol Zn/2 mols HCl) = 0.137 x 1/2 = 0.0685. So you will have left 0.0994 - 0.0685 = ? moles Zn and grams Zn = moles Zn x atomic mass Zn = ?
c) moles H2 produced = 0.137 moles HCl x (1 mol H2/2 mols HCl) = 0.137 x (1/2) = 0.0685. Then grams H2 = moles H2 x molar mass H2 = ?