Question

An aqueous solution is 3.00% by mass dextrose (C6H12O6) in water. If the density of the solution is 1.0097 g/mL, calculate the molarity of dextrose in the solution.

Answer 1

Answer:

[C₆H₁₂O₆] = 0.17M

Explanation:

3% by mass, means 3 g of solute in 100 g of solution.

Density is mass / volume. This data always refers to solution.

Solution density = Solution mass / Solution volume

1.0097 g/mL = 100 g / Solution volume

Solution volume = 100 g / 1.0097 g/mL → 99.03 mL

Let's convert the mL to L, for molarity (mol/L)

99.03 mL = 0.09903 L

Now we have to find out the moles. Let's calculate them with the molar mass

(mass / molar mass)

3 g / 180 g/mol = 0.0166 mol

Molarity is mol/L → 0.0166 mol/0.09903 L → 0.17 M