Show the calculation of the mass of Ca3 (PO4) 2 needed to make 200 ml of a 0.128 M solution.

We need 7.94 grams of Ca3 (PO4) 2

Explanation:

Step 1: Data given

Volume of Ca3 (PO4) 2 = 200 mL = 0.2 L

Molarity = 0.128 M

Molar mass of Ca3 (PO4) 2 = 310.18 g/mol

Step 2: Calculate moles of Ca3 (PO4) 2

Moles = molarity * volume

Moles Ca3 (PO4) 2 = 0.128 M * 0.2 L

Moles Ca3 (PO4) 2 = 0.0256 moles

Step 3: Calculate mass of Ca3 (PO4) 2

Mass Ca3 (PO4) 2 = moles Ca3 (PO4) 2 * molar massCa3 (PO4) 2

Mass Ca3 (PO4) 2 = 0.0256 moles * 310.18 g/mol

Mass Ca3 (PO4) 2 = 7.94 grams

We need 7.94 grams of Ca3 (PO4) 2