a 5% (w/v) solution of cane sugar (mol wt=342) is isotonic with 1% (w/v) solution of substance x. the molecular weight of X is

Ans. is 68.4 g mol​-1

Isotonic means both the solutions have same concentration.

Mass of cane sugar = 5 g dissolved in 100 mL water
Mass of substance x = 1 g dissolved in 100 mL water
Molar mass of cane sugar = 342 g mol-1
Molar mass of substance x = ?

Concentration = Concentration = no. of molesVolume=nV

n=massmolar mass

ncane sugar=5342nx=1Mx

So, on equating the concentrations of both, we can find the molecular mass of substance x:

5342×100=1Mx×100Mx=3425=68.4 g mol-1

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