Question

Choose the correct statment(s) for alkynes :

• A. $\text{Boiling point}\propto \frac{1}{\text{Molar mass}}$
• B. $\text{Melting point}\propto \text{Molar mass}$
• C. Density of alkynes increases with the increase in their molar mass
• D. $\text{Boiling point}\propto \frac{1}{\text{Van der Waals force}}$

Answer 1

Answer: (B), (C)

The correct options are
B $\text{Melting point}\propto \text{Molar mass}$
C Density of alkynes increases with the increase in their molar mass

Physical properties of alkynes :

$\text{(Boiling point, )}\propto \text{Molecular size (or surface area)}$
$\text{Boiling point}\propto \text{van der Waals force}$
$\text{Boiling point}\propto \text{Molar mass}$


$\text{Melting point}\propto \text{Molecular size (or surface area)}$
$\text{Melting point}\propto \text{van der Waals force}$
$\text{Melting point}\propto \text{Molar mass}$

Density :
Density of alkynes increases with the increase in their molar mass
Alkynes are lighter than water