Answer:
0.0225 M
Explanation:
In one liter of this solution, there are 45 mEq of Ca⁺².
1 mEq of Ca⁺² is equal to 20 mg of Ca⁺. We know this by dividing its molar mass (40) by the charge of the ion (2).
Meaning that 45 mEq of Ca⁺² is equal to (45 * 20) 900 mg of Ca⁺².
Now we convert 900 mg of Ca⁺² into moles, using its molar mass:
Finally we calculate the molarity of the solution: