A solution is prepared by dissolving 3.0 g of potassium chlorate (KClO_3) to make a 0.70 mol/L (molarity) solution. What is the volume of the solution in liters?

• A. 0.21 L
• B. 0.061 L
• C. 0.70 L
• D. 0.049 L

Answer: (D)

Verified step by step guidance

1. First, calculate the number of moles of potassium chlorate (KClO_3) using its given mass and molar mass. The molar mass can be found by summing the atomic masses: K (39.1 g/mol), Cl (35.5 g/mol), and O (16.0 g/mol) times 3. Use the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
2. Next, recall the definition of molarity (M), which is moles of solute per liter of solution: \(M = \frac{\text{moles of solute}}{\text{volume of solution in liters}}\).
3. Rearrange the molarity formula to solve for the volume of the solution: \(\text{volume} = \frac{\text{moles of solute}}{M}\).
4. Substitute the number of moles calculated in step 1 and the given molarity (0.70 mol/L) into the rearranged formula to find the volume in liters.
5. Make sure to keep track of units throughout the calculation to ensure the final volume is expressed in liters.