A pure sample of phenol is heated with an excess of zinc dust, yielding exactly 39.0 grams of benzen — Hydrocarbons Chemistry Question

💡 Solution & Explanation

The reaction is $C_6H_5OH + Zn \to C_6H_6 + ZnO$. The molar mass of benzene ($C_6H_6$) is $78 \text{ g/mol}$. 39.0 grams of benzene equates to $\frac{39.0}{78} = 0.5 \text{ moles}$. Since the stoichiometry is 1:1, 0.5 moles of phenol were used. The molar mass of phenol ($C_6H_5OH$) is $(6 \times 12) + (6 \times 1) + 16 = 94 \text{ g/mol}$. Mass of phenol = $0.5 \text{ moles} \times 94 \text{ g/mol} = 47 \text{ grams}$.