(a) What type of deviation is shown by a mixture of ethanol and acetone 7 Give reason.
(b) A solution of glucose (molar mass = 180 g `mol^(-1)`) in water is labelled as 10% (by mass). What would be the molallty and molarity of the 90lution ? (Density of solution = 1.2 g `mL^(-1)`.)

Explanation

(a) It shows positive deviation. It is due to weaker interaction between acetone and ethanol than ethanol-ethanol interactions.
(b) Given : `W_(B) = 10 g , W_(s) = 100 g , W_(A) = 90 ` g
`M_(B) = 180 g//mol & d = 1.2 `g/mL
M = `(Wt % xx "density" xx 10)/("Mol.wt.")`
M = `(10 xx 1.2 xx 10)/(180)`
= 0.66 M or 0.66 mol/L
= 0.66 M
m = `(W_(B) xx 1000)/(M_(B) xx W_(A) "(in g)") `
`m = (10 xx 1000)/(180 xx 90)`
= 0.61 m or 0.61 mol/kg