Answer:
9.45 × 10⁻³ M
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
