[Seta Akamatsu]

Could someone please explain to me simply and clearly how to I find the H+ concentration  of a sample or the OH- concentration of a sample or the pOH of a sample.

An example of this is lets say I have an unknown water sample that has a pH of 0.5, which I know is very acidic. How do I find these various concentrations listed above and what do the formulaes mean in getting those concentrations. As in what does the numbers and letters or log, or I'm not even sure.

I would please just want someone to explain this in as simplistic, easy way as possible, Chemistry is a difficult subject for me. Thank you for your help 

[mike]

H⁺ can be determined in some cases by measuring the pH of the solution with pH paper or a pH meter.

For this you must know that pH = -log₁₀[H⁺]   where [H⁺] = concentration of H⁺

In your example: pH = 0.5 this means that [H⁺] = 0.316 mol/L

and: pH + pOH = 14, so pOH = 13.5 (pOH = -log₁₀[OH^-])

For more good reading on acids and bases check out: http://www.chembuddy.com/