Question

Which of the following aqueous solutions will exhibit highest boiling point ?

• A. $0.01 \,M$ urea
• B. $0.01 M KNO _{3}$
• C. $0.01 \,M\, Na _{2} SO _{4}$
• D. $0.015\, M\, C _{6} H _{12} O _{6}$

Answer 1

Answer: (C)

$0.01 \,M\, Na _{2} SO _{4}$

Answer 2

$NH _{2} CONH _{2} \longrightarrow$no dissociation

$KNO _{3} \longrightarrow K ^{+}+ NO _{3}^{-} ; \,\,\,\,i=2$
$Na _{2} SO _{4} \longrightarrow 2 Na ^{+}+ SO _{4}^{2-} ; \,\,\,\,\, i=3$
$C _{6} H _{12} O _{6} \longrightarrow$ no dissociation

As $Na _{2} SO _{4}$ gives naximum particles, i.e., $3$ on dissociation boiling point is maximum for $Na _{2} SO _{4}$.