Question

If $F$ represents the strength of cohesive force, then what will be the correct order for strength of cohesive force for solid, liquid and gas ?

• A. $F_{solid}<F_{liquid}<F_{gas}$
• B. $F_{solid}>F_{liquid}>F_{gas}$
• C. $F_{solid}<F_{liquid}=F_{gas}$
• D. $F_{liquid}>F_{gas}>F_{solid}$

Answer 1

The correct option is B $F_{solid}>F_{liquid}>F_{gas}$

$\Rightarrow$Cohesive forces are weak intermolecular forces and operate within a short range only, hence the strength of cohesive force weakens if the distance between molecules increases.
$\because$ Distance $\left(r\right)$ between molecules in gases, liquids and solid is in the order,
$r_{gas}>r_{liquid}>r_{solid}$
$\therefore$Order of strength of cohesive force for solid, liquid and gases are
$F_{solid}>F_{liquid}>F_{gas}$