Question
Using ethanol’s density of 0.789 g/mL, calculate the molarity of ethanol in a beer marked as 5.6%
alcohol. (Hint: 5.6% means 5.6mL of ethanol for every 100mL of solution)
So I know the formula for Molarity is Number of Moles/ Liters of Solution, however I'm confused on how to apply it, or even if it is applied to solve this question. Any help is deeply appreciated.
Mary
alcohol. (Hint: 5.6% means 5.6mL of ethanol for every 100mL of solution)
So I know the formula for Molarity is Number of Moles/ Liters of Solution, however I'm confused on how to apply it, or even if it is applied to solve this question. Any help is deeply appreciated.
Mary
Answers
DrBob222
If you have 5.6 mL ethanol in 100 mL solution, then you have 56 mLethanol in 1 L of solution.
How many grams is that? mass = volume x density = 56 x 0.789 = ? grams ethanol. How many moles is that? That's
mols = grams/molar mass. You have grams and you have molar mass. Solve for mols
Then M = mols/L solutiion and you have it.
How many grams is that? mass = volume x density = 56 x 0.789 = ? grams ethanol. How many moles is that? That's
mols = grams/molar mass. You have grams and you have molar mass. Solve for mols
Then M = mols/L solutiion and you have it.