The drinking water standard for nitrate is 10 mg/l as n (i. e., drinking waters should not exceed this value). what quantity of nitrate ion does this concentration represent?

This concentrations represents 9.71 x 10¹⁹  nitrate ions per litre of drinking water.

Explanation:

Nitrate: NO₃⁻

MW = 62.00 g/mol

1 mol = 6.022 x 10²³

62 g  NO₃⁻ 6.022 x 10²³ ions

10 x 10⁻³ g NO₃⁻ x

x = 9.71 x 10¹⁹ ions

This concentrations represents 9.71 x 10¹⁹  nitrate ions per litre of drinking water.

6.4 cm (max) - 25 cm (min)