Question

$0.037\, g$ of an alcohol, $R$-OH was added to $C _{2} H _{5} MgI$ and the gas evolved measured $11.2\, cc$ at STP. The molecular mass of $R- OH$ will be

• A. 47
• B. 79
• C. 77
• D. 74

Answer 1

Answer: (D)

74

Answer 2

$\because 11.2\, cc$ gas is evolved by alcohol $=0.037\, g$ $\therefore 22400\, cc$ gas will be evolved by alcohol $=\frac{0.037}{11.2} \times 22400$ $=74\, g$