A solution contains. 36 g sodium hydroxide in 500 ml what is the ph

NaOH is a strong base therefore complete dissociation takes place.

number of NaOH moles dissolved - 0.36 g / 40 g/mol = 0.009 mol

Concentration of NaOH - 0.009 mol / 0.5 L = 0.018 M

molar ratio of NaOH to OH⁻ is 1:1, therefore [NaOH] = [OH⁻]

pOH = - log [OH⁻]

pOH = - log (0.018)

pOH = 1.74

pH + pOH = 14

pH = 14 - 1.74

pH = 12.26