4.7 g of phenol is heated with Zn to give product X. If this reaction goes to 60% completion then the number of moles of compound X formed will be 10-2. (Nearest Integer) (Given molar mass in g mol-1 : H:1, C:12, O:16)
Answer
3
Solution
Phenol is reduced to benzene on heating with zinc dust:
C6H5OH + Zn C6H6 + ZnO ⇒ X = benzene
Molar mass of phenol = 6(12) + 6(1) + 16 = 94 g mol-1
Moles of phenol = 4.794 = 0.05 mol
1 mol phenol gives 1 mol benzene; at 60% completion:
Moles of X = 0.05 × 0.60 = 0.03 = 3 × 10-2 mol
Answer: 3