Calculate the pH of a solution formed by mixing equal volumes of two solutions A and B of a strong acid having pH = 6 and pH = 4 respectively.
pH of solution A = 6
Therefore, concentration of [H+ ] ion in solution A = 10-6 mol L-1
pH of solution B = 4
Therefore, concentration of [H+ ] ion in solution B = 10-4 mol L-1 .
On mixing one litre of each solution, total volume = 1L + 1L = 2L.
Amount of H+ ions in 1L of solution A= concentration x volume V= 10-6 mol X 1L
Amount of H+ ions in 1L of solution B= 10-4 mol X 1L
The total amount of H+ ions in the solution formed by mixing solutions A and B is (10-6 + 10-4 ) mol X 1L
This amount is present in 2L solution.
Therefore,
Hence, the pH will be 4.3