What is the concentration of hydroxide ions in a solution with a pH of 7.55?

2.82 * 10-8

3.55 * 10-7

9.36 * 10-3

4.17 * 10-11

PH+pOH=14 so we solve for pOH

•pOH=14-7.55 - > 6.45

Now we use the pOH formula

•pOH=-log[OH-] (what’s inside brackets its the concentration of OH)

•6.45=-log[OH] now we pass the negative to the other side

•-6.45=log[OH] and an easy way is to rise 10 by that number

•10^-6.44 = [OH]

•OH = 3.55x10^-7 M