Question

What is the molarity of a solution with 12.90 grams of solute and a volume of2,130.0 mL? The solute has a molar mass of 189.7 g/mol.

Answer 1

We are required to calculate the molarity (or concentration).

Given:

mass = 12.90 g

volume = 2130.0 mL

molar mass = 189.7 g/mol

The formula for molarity:

`C\text{ = }(n)/(V)`

where n is the number of moles and v is the volume.

We can calculate the number of moles:

n = m/M where m is the mass and M is the molar mass

n = 12.90g/189.7g/mol

n = 0.0680 mol

To calculate the molarity we need to convert the volume from mL to L

v = 2130.0 mL = 2.130 L

C = n/V

C = 0.0680mol/2.130L

C = 0.0319 mol/L (or M)

Therefore the molarity = 0.0319 mol/L