To calculate the molarity (M) of a solution, you can use the formula:
\[ \text{Molarity (M)} = \frac{\text{moles of solute}}{\text{liters of solution}} \]
- Calculate the number of moles of potassium nitrate (KNO₃). First, find the molar mass of KNO₃:
- Potassium (K): 39.10 g/mol
- Nitrogen (N): 14.01 g/mol
- Oxygen (O): 16.00 g/mol (there are 3 oxygen atoms, so multiply by 3)
\[ \text{Molar mass of KNO}_3 = 39.10 , \text{g/mol} + 14.01 , \text{g/mol} + (16.00 , \text{g/mol} \times 3) = 39.10 + 14.01 + 48.00 = 101.11 , \text{g/mol} \]
- Calculate the moles of KNO₃:
\[ \text{Moles of KNO}_3 = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} = \frac{60.0 , \text{g}}{101.11 , \text{g/mol}} \approx 0.593 , \text{mol} \]
- Calculate the molarity:
\[ \text{Molarity} = \frac{0.593 , \text{mol}}{3.00 , \text{L}} \approx 0.198M \]
Therefore, the molarity of the solution is 0.198 M.
The correct answer is a 0.198M.