Richard P. answered • 09/25/20
Tutor
New to Wyzant
The formula for freezing point depression is
ΔT = Kf M where M is the molality
For this case M = (26 / MM) / .25 where MM is the Molar mass of the unknown
Rearranging this and substituting for Kf and ΔT results in MM = 193.6 which rounds to 194 g/mole
Richard P.
The problem said molecular compound. That means not ionic. Thus i = 1
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09/26/20
J.R. S.
Actually, you cannot legitimately answer this question unless you know if the unknown compound is an electrolyte or a non electrolyte. If an electrolyte, you would then need to know how many ions it produces so that you could estimate the van't Hoff factor. The actual formula you would use is ∆T = imK where i is the van't Hoff factor.09/26/20