How many grams of ethanol, CH3CH2OH, should you dissolve in water to make 0.800 L of vodka (which is an aqueous solution that is

Question

3 years ago

9

6.86 M ethanol)?

1 answer:

Rashid [163] · Answer 1 · 2021-11-30T22:56:52+03:00

Answer:

252.5g

Explanation:

Given parameters:

Volume of vodka = 0.8L

Molarity of ethanol = 6.86M

Unknown:

Mass of ethanol = ?

Solution:

Molarity is one of the ways of expressing concentration. It is the number of moles of a substance in a solution.

Since Vodka = ethanol + water = solution

Molarity = $\frac{number of moles of ethanol}{Volume of solution}$

Number of moles of ethanol = molarity of vodka x volume of solution

Once we obtain the number of moles, we can derive the mass of the ethanol;

Number of moles = 6.86M x 0.8L = 5.49moles

Mass of ethanol = number of moles x molar mass

molar mass of ethanol = 12 + 3(1) + 12 + 2(1) + 16 + 1 = 46g/mol

Mass of ethanol = 5.49 x 46 = 252.5g