What is the molecular mass of a substance if 22.5 g dissolved in 250 g of water produces a solution whose freezing point is -0.930°C?
The molecular mass is 180 u.
The formula for freezing point depression is
#color(blue)(|bar(ul(color(white)(a/a) ΔT_"f" = K_"f"mcolor(white)(a/a)|)))" "#
We can rearrange the formula to get
In your problem,
The molar mass is 180 g/mol, so the molecular mass is 180 u.