Question

calculate the molarity of:

A) 1.50g of aluminum sulfate in a 2000ml solution

B) 0.0282g of Calcium Nitrate in a 1.0 ml solution

Answer 1

A)

Number of moles of aluminum sulfate = mass of aluminum sulfate / molar mass of aluminum sulfate

Number of moles of aluminum sulfate = 1.50 g / 342.15 g/mol = 0.00438 mole

Molarity = number of moles of aluminum sulfate / volume of solution in L

Molarity = 0.00438 mole / 2 = 0.00219 M

B)

Number of moles of Calcium Nitrate = mass of Calcium Nitrate / molar mass of Calcium Nitrate

Number of moles of Calcium Nitrate = 0.0282 g / 164.088 g/mol = 1.72*10^-4

Molarity = number of moles / volume of solution in L

Molarity = 1.72*10^-4 / 0.001 L = 0.172 M