What is the poh of a
2.6 x 10-6 m h+ solution?

Explanation:

pH and pOH

The pH is a way of expressing the hydrogen ion concentration.

pH = -log[H+] where [x] means "the concentration of x in moles per liter."

From pH you can compute pOH since at 25C pH + pOH = 14.00 (but only at 25C)

pH = -log(2.6x10^-6) = 5.585 which should be rounded to two significant digits: pH = 5.59

When taking the log of a number, only the digits to the right of the decimal reflect the precision in the original number. Since 2.6x10^-6 has two significant digits, a pH of 5.59 has two significant digits.

pOH + pH = 14.00

pOH = 14.00 - pH = 14.00 - 5.59 = 8.41 at 25C

We can also use the H+ ion concentration to get the hydroxide ion concentration and from that the pOH.

Kw = [H+][OH-] = 1.00x10^-14 at 25C like any Kc, the value changes with temperature

[OH-] = Kw / [H+] = 1.00x10^-14 / 2.6x10^-6 = 3.846x10^-9 to a couple of guard digits

pOH = -log[OH-] = -log(3.846x10^-9) = 8.415 round to two significant digits: pOH = 8.42 at 25C

Just for grins, you might want to know how Kw changes with temperature, and how [H+] and [OH-] are related at some other temperatures. The pH is the pH of a neutral solution at various temperatures. For instance at 10C a neutral solution has a pH of 7.27. That's not a basic pH. 7.27 is the pH of a neutral solution, but at a different temperature. In a neutral solution at 10C [H+] = [OH-] = 5.41x10^-8M.

pH and Kw for a neutral solution at different temperatures

T pH Kw

0 7.47 0.114 x 10-14

10 7.27 0.293 x 10-14

20 7.08 0.681 x 10-14

25 7.00 1.008 x 10-14

30 6.92 1.471 x 10-14

40 6.77 2.916 x 10-14

50 6.63 5.476 x 10-14

100 6.14 51.3 x 10-14

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.