The freezing point depression constant for water is 1. 86^(@)K gm mol ^(-1). If 5g Na _(2) SO_(4) is dissolved in 45 g water, the depression in freezing point is 3.64 ^(@)C. The van't Hoff factor for Na _(2) SO _(4) is ……

The freezing point depression constant for water is 1. 86^(@)K gm mol

1.	The freezing point depression constant for water is 1. 86^(@)K gm mol ^(-1). If 5g Na _(2) SO_(4) is dissolved in 45 g water, the depression in freezing point is 3.64 ^(@)C. The van't Hoff factor for Na _(2) SO _(4) is ……
Answer» `2.50` `2.63` `3.64` `5.50` Solution :`K _(f) = 1. 86 , W_(2) = 5g, DELTA T _(f ) =3.64, M _(2) = 142, W_(1) = 45 g` `Delta T_(f) = I xx K _(f)` `i = (Delta T _(f) xxM _(2) xx W_(1))/( K _(f) xx W _(2) xx 1000)` `= (3.64 xx 142 xx 45)/(1. 86 xx 5 xx 1000)` `i = 2.5`