A bottle of vintage port wine has a volume of 750ml and contains 135ml ethanol. Ethanol has a density of 0.789g/ml. What is the molarity?
M = mols ethanol/L solution.
What else do you need to know?
To find the molarity of ethanol in the bottle of vintage port wine, we need to first calculate the number of moles of ethanol in the bottle, and then divide it by the volume of the solution (port wine) in liters.
Step 1: Calculate the mass of ethanol in grams.
Mass = Density x Volume
Mass = 0.789g/ml x 135ml
Mass = 106.215g
Step 2: Convert the mass of ethanol to moles.
Molar mass of ethanol (C2H6O) = 46.07 g/mol
Moles = Mass / Molar mass
Moles = 106.215g / 46.07g/mol
Moles ≈ 2.307 mol
Step 3: Convert the volume of the solution (port wine) to liters.
Volume = 750ml = 0.75L
Step 4: Calculate the molarity.
Molarity (M) = Moles / Volume
Molarity = 2.307 mol / 0.75 L
Molarity ≈ 3.076 M
Therefore, the molarity of ethanol in the bottle of vintage port wine is approximately 3.076 M.
To find the molarity of a solution, we need to know the amount of solute (in moles) and the volume of the solution (in liters).
First, let's convert the volume of ethanol from milliliters to liters by dividing by 1000:
135 ml / 1000 = 0.135 L
Next, we need to find the number of moles of ethanol. We can do this by using the formula:
Moles = Mass / Molar Mass
The molar mass of ethanol (C2H5OH) is calculated by summing the atomic masses of carbon (C), hydrogen (H), and oxygen (O). The atomic masses can be found in the periodic table:
C = 12.01 g/mol
H = 1.008 g/mol
O = 16.00 g/mol
Molar Mass of C2H5OH = 2(12.01) + 6(1.008) + 16.00 = 46.07 g/mol
Now, we can calculate the number of moles of ethanol:
Moles = 0.135 L * (0.789 g/ml) / (46.07 g/mol) = 0.002319 mol
Finally, we can find the molarity (M) by dividing the number of moles by the volume of the solution in liters:
Molarity = Moles / Volume (L) = 0.002319 mol / 0.750 L = 0.0031 M (rounded to four significant figures)
Therefore, the molarity of the ethanol in the vintage port wine is approximately 0.0031 M.