chemistry
posted by katie on .
A solution of NaOH(aq) contains 6.2 g of NaOH(s) per 100.0 mL of solution. Calculate the pH and the pOH of the solution at 25 °C.

moles NaOH = grams/molar mass
M = moles NaOH/L soln.
(OH^) = M NaOH
pOH = log(OH^)
Use pH + pOH = pKw = 14 to convert pOH to pH.
Then convert pH to (H^+) by
pH = log(H^+). 
i didn't know ph could be greater than 14 and poh less than 0

It can.
For example, if M HCl = 0.1M, then (H^+) = 0.1 and pH = 1
If M HCl = 1.0, then (H^+) = 1.0M and pH = log(1.0) = 0
If M HCl = 10.0, then (H^+) = 10.0M and pH = log(10) = log(1) = 1.
We usually work with pH values for solns in the 0.1 and smaller range; therefore, the pH is always greater than zero and positive. In fact, when the pH scale was first devised, the negative sign was put in the definition (pH = log(H^+) for the expressed purpose of making the number a positive number since the log of numbers less than 1 are negative.