What is the percent by volume (% v/v) of a solution made by mixing 12 ml of ethanol (C2H5OH) with 48 ml of water?

b) Assuming the density of ethanol is 0.789g/ml, what is the molarity of this solution?

Assuming 12 mL ethanol + 48 mL H2O = 60 mL (not a true assumption),

(12 mL/60)*100 = ?

b. 12 mL ethanol has a mass of
m = volume x density = 12*0.789 = about 9.46 g convert to mols = g/molar mass = about 0.205 mols. Again, assuming the volume is 60 cc (not true), then M = mol/L soln = 0.205/0.06 = ?

To find the percent by volume (% v/v) of a solution, you need to calculate the ratio of the volume of the solute (ethanol) to the total volume of the solution (ethanol + water) and multiply by 100.

a) Percent by volume (% v/v):
Step 1: Calculate the total volume of the solution.
Total volume of the solution = volume of ethanol + volume of water
Total volume = 12 ml + 48 ml = 60 ml

Step 2: Calculate the percent by volume.
% v/v = (volume of ethanol / total volume) x 100
% v/v = (12 ml / 60 ml) x 100
% v/v = 20%

b) Molarity is a measure of concentration and represents the number of moles of solute (ethanol) per liter of solution.

To find the molarity of a solution, you need to calculate the number of moles of the solute and divide it by the volume of the solution in liters.

Molarity (M) = moles of solute / volume of solution (in liters)

The number of moles of ethanol can be calculated using its mass and molar mass.

Step 1: Calculate the mass of ethanol.
Mass of ethanol = volume of ethanol x density of ethanol
Mass of ethanol = 12 ml x 0.789 g/ml = 9.468 g

Step 2: Calculate the number of moles of ethanol.
Number of moles of ethanol = mass of ethanol / molar mass of ethanol
Molar mass of ethanol (C2H5OH) = (2 x molar mass of carbon) + (6 x molar mass of hydrogen) + molar mass of oxygen
Molar mass of carbon = 12.01 g/mol
Molar mass of hydrogen = 1.008 g/mol
Molar mass of oxygen = 16.00 g/mol

Molar mass of ethanol = (2 x 12.01 g/mol) + (6 x 1.008 g/mol) + 16.00 g/mol
Molar mass of ethanol = 46.07 g/mol

Number of moles of ethanol = 9.468 g / 46.07 g/mol
Number of moles of ethanol = 0.2055 mol

Step 3: Convert the volume of the solution to liters.
Volume of the solution = 60 ml = 0.06 L

Step 4: Calculate the molarity.
Molarity (M) = moles of solute / volume of solution (in liters)
Molarity (M) = 0.2055 mol / 0.06 L
Molarity (M) = 3.425 M

Therefore, the molarity of this solution is 3.425 M.