Question

Question: There is about 1.0g of calcium, as Ca²⁺, in 1.0 L of milk. What is the molarity of Ca²⁺ in milk?

Short answer

The molarity of Ca²⁺ in milk is 0.025M.

Step-by-step solution

Determine number of moles

Given the mass of Ca²⁺= 1.0g

Given the volume of solution (here milk) = 1L

Again, number of moles = (Given mass of Ca²⁺)/(Molar mass of Ca²⁺)

= (1.0g/40.08g/mol)

= 0.025 mol

Determine the Molarity

Molarity of a solution = Number of moles of Ca²⁺ / Volume of the solution.

Therefore, by substituting the values, we get

Molarity = 0.025 mol/1L

= 0.025mol/L