Stuck on chem problem due tonight

Question

What is the hydroxide ion concentration of a solution that has a pOH of 4.5? Hydrogen ion concentration round to 3 sig figs

Answer 1

To solve this problem we use the pOH formula,

where,

pOH = -log[OH-]

Now we solve for OH- concentration

-pOH = log[OH-]

10^(-pOH) = [OH-]