Question

Water treatment plants must reduce phosphate levels to 3.2 micromoles PO₄³⁻/L before the water is considered drinkable. If water from Lake Pontchartrain is determined to have a phosphate concentration of 0.312 mg PO₄³⁻L, does it meet this allowable standard for drinking water? Show your work!

Answer 1

The water from Lake Pontchartrain has a phosphate concentration of 3.2842 micromoles PO4^3-/L. It does not meet the standard for drinkable water.

Step-by-step explanation:

To determine if the water from Lake Pontchartrain meets the allowable standard for drinking water regarding phosphate levels, we first need to convert the concentration from milligram per liter to micromoles per liter. The molar mass of PO43- is approximately 95 g/mol.

Given that 0.312 mg PO43-/L is the concentration of phosphate in Lake Pontchartrain. We convert this to moles/L (or micromoles/L) using the following steps: 0.312 mg/L * (1 g / 1000 mg) * (1 mol / 95 g) = 3.2842 * 10-6 mol/L = 3.2842 micromoles PO43-/L.

This value is slightly above the allowable standard of 3.2 micromoles PO43-/L. Therefore, the water from Lake Pontchartrain does not meet the allowable standard for phosphate levels in drinkable water.