well to go from H+ to pOH, you have to convert H+ to pH first.
H+ = 7.5 x 10^-2
Formula to get pH = pH= -log(H+)
Plug H+ in: pH= -log(7.5x10^-2)
pH= 1.125
now to get pOH we convert pH to pOH
formula for pOH= pOH=14-pH
plug pH in: pOH= 14- 1.125
Answer: 12.875
Hope this helps :)
