The values of Van’t Hoff factors for KCl,NaCl, Glucose and $K_{2}S{O}_4$ respectively are 

1-Answer : if 100% ionized, No.of ions = vant hoff factor 

$KCl\underset{ }{\overset{ }{\to }}{K}^{+}+C{l}^{-}i=2$

$NaCl\underset{ }{\overset{ }{\to }}N{a}^{+}+C{l}^{-}i=2$

Glucose$\underset{ }{\overset{ }{\to }}$ i =1

$K_{2}S{O}_4\underset{ }{\overset{ }{\to }}2K^{+}S{O}_4^{-2}i=3$