Assume that acid rain has lowered the pH of a particular lake to pH 4.0.What is the hydroxyl ion concentration of this lake?

A)1 × 10⁻¹⁰ mol of hydroxyl ion per litre of lake water
B)1 × 10⁻⁴ mol of hydroxyl ion per litre of lake water
C)10.0 M with regard to hydroxyl ion concentration
D)4)0 M with regard to hydroxyl ion concentration
E)1 × 10⁻⁴ mol of hydroxyl ion per litre of lake water and 4.0 M with regard to hydrogen ion concentration