Question

You want to determine the concentration of a solid solute dissolved in a specified volume of liquid solvent which of the following would be the best to use?
a) volume/volume percent
b) molarity
c)mass/mass percent
d)mole fraction

Answer 1

The answer is: b) molarity.

Molar concentration (molarity) is a measure of the concentration of a solute in a solution.

Unit for molarity (c = n/V) is the number of moles (n) per litre (V), having the unit symbol mol/L or sometimes mol/dm³.

For example:

m(NaOH) = 80.0 g; mass of solide solute.

n(NaOH) = m(NaOH) ÷ M(NaOH).

n(NaOH) = 80 g ÷ 40 g/mol.

n(NaOH) = 2 mol.

V(NaOH) = 500 mL ÷ 1000 mL/L.

V(NaOH) = 0.5 L; a specified volume of liquid solvent.

c(NaOH) = n(NaOH) ÷ V(NaOH).

c(NaOH) = 2 mol ÷ 0.5 L.

c(NaOH) = 4 mol/L.

Answer 2

Generally, chemists prefer to use morality (B) because it only invovles measuring the final volume of the solution and amount of moles of the solute

Hope this helps