Aqueous HCl reacts with MnO2(s) to form MnCl2(aq), Cl2(g), and H2O(l). What is the weight (in g) of Cl2 liberated when 8.7 g of MnO2(s) is reacted with excess aqueous HCl solution? (Given Molar mass in g mol-1 Mn = 55, Cl = 35.5, O = 16, H = 1)
- 14.2
- 21.3
- 7.1
- 71
Answer
(3) 7.1
Solution
Balanced equation:
MnO2 + 4HCl MnCl2 + Cl2 + 2H2O
1 mol MnO2 gives 1 mol Cl2
Molar mass of MnO2 = 55 + 2 16 = 87 g mol-1
nMnO2 = 8.787 = 0.1 mol
nCl2 = 0.1 mol
Mass of Cl2 = 0.1 71 = 7.1 g
Answer: (3)