<prompt> In a solution the concentration of hydrogen ion is 1 x 10-7 moleslitre at 25degC. The pH of the solution will be:ThreeSevenNineTwelve  <response>: The term pH is defined as the negative log of the hydrogen ion concentration; that is, For the given solution at 25degC, Low pH values correspond to high concentrations of H and high pH values correspond to low concentrations of H. Ref: Kennelly P.J., Rodwell V.W. 2011. Chapter 2. Water pH. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell Eds, Harpers Illustrated Biochemistry, 29e. 