Arrange the pH values of 0, 2, 4 and 6 in the increasing value of H+ (aq) ions conc.?
The smaller the pH the more the H+ (aq) ions concentration would be.
Hence, the pH values of 0, 2, 4 and 6 in the increasing value of H+ (aq) ions concentration is: -
6 < 4 < 2 < 0