Question

What is the molarity of a solution formed by dissolving 155 mg of calcium nitrate in

enough water to make 100. mL of solution

Answer 1

9.45 × 10⁻³ M

Step-by-step explanation:

Step 1: Given data

• Mass of calcium nitrate (solute): 155 mg (0.155 g)

• Volume of solution: 100. mL (0.100 L)

Step 2: Calculate the moles of solute

The molar mass of Ca(NO₃)₂ is 164.09 g/mol.

0.155 g × 1 mol/164.09 g = 9.45 × 10⁻⁴ mol

Step 3: Calculate the molarity of the solution

The molarity is equal to the moles of solute divided by the liters of solution.

M = 9.45 × 10⁻⁴ mol/0.100 L = 9.45 × 10⁻³ M