Answer: pH=7.30 (2 sig figs means going 2 places past the decimal point since we are using logs.)
pOH=6.70
[OH-]=2.0x10^-7 M
Explanation: To get pH, you have to take the -log of the concentration of hydronium ions. To find pOH, subract pH from 14. To get [OH-] we need to do 10^-pOH to go in reverse essentially. Hope this helps.