In: Chemistry
You add 0.535 g of NaOH to 100.0 mL of water at 25
Molar mass of NaOH = atomic mass of Na + atomic mass of O + atomic mass of H
= 23 + 16 + 1
= 40 gmol -1
Given mass of NaOH , M = 0.535 g
So no.of moles ,
Molarity of the solution ,
M = 0.134 M
NaOH Na+ + OH -
1 mole of NaOH produces 1 mole of OH-
So concentration of [OH-] = concentration of NaOH
= 0.134 M
pOH = - log[OH-]
= - log 0.134
= 0.87
pH = 14-pOH
= 14-0.87
= 13.13
pH = -log[H3O+]
[H3O+]= 10-pH
= 10 -13.13
= 7.4810-14 M