How many moles of CaCl_2 are present in 250 mL of a 3.0 M CaCl_2 solution?

• A. 0.75 moles
• B. 1.5 moles
• C. 0.25 moles
• D. 3.0 moles

Answer: (A)

Verified step by step guidance

1. Identify the given information: the volume of the solution is 250 mL and the molarity (M) of the CaCl_2 solution is 3.0 M.
2. Convert the volume from milliliters to liters because molarity is expressed in moles per liter. Use the conversion: \$1 \, \text{L} = 1000 \ \text{mL}\(, so \)250 \ \text{mL} = \frac{250}{1000} \ \text{L}$.
3. Recall the definition of molarity: \(M = \frac{\text{moles of solute}}{\text{liters of solution}}\). Rearranged to find moles, it becomes \(\text{moles of solute} = M \times \text{liters of solution}\).
4. Substitute the known values into the equation: multiply the molarity (3.0 M) by the volume in liters (from step 2) to find the number of moles of CaCl_2.
5. Calculate the product to find the moles of CaCl_2 present in the 250 mL solution.