You dissolve 20.0 gms of sucrose (sugar) in 200 mL of ethanol 20ºC (density of ethanol at 20ºC is 0.789 gm/ml). What is the mass % of the solute?

mass ethanol = volume x density = ?.

[20/(20+ ?g EtOH)]*100 = ?

To find the mass percent of the solute in a solution, you need to determine the mass of the solute (sucrose) and the total mass of the solution.

First, let's calculate the mass of the solute (sucrose):

Mass of solute = 20.0 g

Next, we need to calculate the total mass of the solution, which includes the mass of the solute (sucrose) and the mass of the solvent (ethanol).

The volume of the solvent (ethanol) is given as 200 mL, and the density of ethanol at 20ºC is 0.789 g/mL.

So, the mass of the solvent (ethanol) can be calculated as follows:

Mass of solvent = Volume of solvent * Density of solvent
= 200 mL * 0.789 g/mL
= 157.8 g

Now, we can calculate the total mass of the solution:

Total mass of solution = Mass of solute + Mass of solvent
= 20.0 g + 157.8 g
= 177.8 g

Finally, we can calculate the mass percent of the solute (sucrose) in the solution:

Mass percent of solute = (Mass of solute / Total mass of solution) * 100
= (20.0 g / 177.8 g) * 100
≈ 11.25%

Therefore, the mass percent of the solute (sucrose) in the solution is approximately 11.25%.