Question

A 7.73 mass % aqueous solution of ethylene glycol (HOCH2CH2OH) has a density of 1.19 g/mL. Calculate the molarity of the solution. Give your answer to 2 decimal places.

Answer 1

Answer:

Molarity for the solution is 1.48 M

Explanation:

Molarity involves the moles of solute that are contained in 1L of solution. It is a sort of concentration. The most usual.

7.73 by mass involves the mass of solute that are contained in 100 g of solution, so this one of ethylene glycol contains 7.73 g of it.

Let's determine the moles of solute

7.73 g / molar mass of ethylene glycol = moles

7.73 g / 62 g/mol = 0.124 mol

If the mass of solution is 100 g, we can determine the volume with density.

Density = Mass / Volume

Volume = Mass / Density

Volume = 100 g / 1.19 g/mL = 84.03 mL

In conclusion, 0.124 moles are contained in 84.03 mL

Molarity is mol/L, so let's convert the volume in L

84.03 mL . 1L / 1000 mL = 0.08403 L

0.124 mol / 0.08403 L = 1.48 M