What is the concentration moles/liter of nitric acid solution having PH of 4?

Explanation

To determine the concentration of nitric acid in moles per liter with a pH of 4, we apply the formula: pH = -log[H+]. Rearranging gives [H+] = 10-pH. Substituting pH = 4 yields [H+] = 10-4 = 0.0001 mol/L. Since HNO3 dissociates completely in solution, the concentration of HNO3 is equal to the concentration of H+ ions. Thus, the correct concentration is 0.0001 mol/L.Option B (-4) is incorrect because pH cannot be a negative concentration. Option C (10-4) is mathematically correct but usually expressed as 0.0001 mol/L for clarity. Option D (10-10) would relate to a much higher pH value, unsuitable for this question.