If a liter of solution is needed, how many grams of ethanol, C2H6O will be added when a scientist creates a 0.25 molal solution?
The scientist must add 11.3 g ethanol.
Step 1. Calculate the mass of 1 L solution
To convert mass to volume, we need the density of the solution. It should be slightly less than that of water.
I shall assume that the density is 0.996 g/mL.
Step 2. Calculate the mass of ethanol in 1000 g water
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Thus, a 0.25 mol/kg solution will contain 0.25 mol ethanol and 1000 g water.
Thus, the solution contains 11.5 g ethanol in 1011.5 g solution
Step 3. Calculate the mass of ethanol in 1 L solution
Mass of 1 L solution = 996 g