Question

Hard water normally contains mineral ions, such as Ca²⁺ and Mg²⁺ ions, from minerals that dissolved in the ground water. For water of low hardness, the concentration of Ca²⁺ ions is usually expressed as ppm CaCO₃ in the water sample. Parts per million (ppm) is defined as one part of solute mass per 1,000,000 parts of solution mass, as shown in the following equation. Please note, the unit of denominator and numerator needs to be the same.

Since ppm expresses the concentration of dilute solutions, the density of water is approximately 1 g/mL. One ppm is equivalent to 1 milligram of solute per liter of water sample (mg/L).

1 ppm = 1 mg/L

The following figure shows the conceptual plan to convert the mole number of metal ions to ppm CaCO₃.

Question:

Suppose the mole number of Ca²⁺ ions in a 50 mL water sample is quantified as 1.5

Answer 1