Question

The correct order of boiling point for primary $(1^{∘})$ , secondary $(2^{∘})$ and tertiary $(3^{∘})$ alcohols is

• A. $1^{∘}>2^{∘}>3^{∘}$
• B. $3^{∘}>2^{∘}>1^{∘}$
• C. $2^{∘}>1^{∘}>3^{∘}$
• D. $2^{∘}>3^{∘}>1^{∘}$

Answer 1

Answer: (A)

Alcohols with same molecular weight ate expected to have almost same boiling point, however two more factors other than molecular weight are important; they are namely H-bonding and surface area of molecule. Both these factors are least in $3^{∘}$ alcohols and maximum in $1^{∘}$ alcohols. Hence, $3^{∘}$ alcohols have least boiling point while $1^{∘}$ alcohols have maximum boiling point.