Question

According to the principle of electrical neutrality, a water sample must have the same number of anions and cations. Assuming that a water sample contains 40 mg/L of chloride, 100 mg/L sulfate, and 10 mg/L nitrate, estimate the maximum amount (in mg/L) of sodium that could be present in this water sample.

Answer 1

1. Convert 40 mg/L Cl^-, 100 mg/L SO4^2-, and 10 mg/L NO3^- into moles/liter using the formula masses for Cl, SO4, and NO3.
2. Add the moles of the three anions to get the total moles/liter.
3. Convert the total moles/L to grams of Na+/L by multiplying the total moles/L by the atomic mass of Na.