What amount of solid NaOH must be added to 1.0 L of a 0.14 M H2CO3 solution to produce a solution with [H+]= 3.5×10−11 M ? There is no significant volume change as the result of the addition of the solid.

mass NAOH = 0.0114 g

Explanation:

∴ C H2CO3 = 0.14 M

∴ V sln = 1 L

∴ [H3O+] = 3.5 E-11 M

∴ pH = - Log [H3O+]

⇒ pH = 10.456

∴ 14 = pH + pOH

⇒ pOH = 3.544

⇒ [OH-] = 2.8571 E-4 M

∴ C NaOH = [OH-]

⇒ C NaOH = 2.8571 E-4 M

⇒ mol NaOH = (2.8571 E-4 mol/L)*( 1 L ) = 2.8571 E-4 mol

∴ molar mass NaOH = 39.997 g/mol

⇒ mass NaOH = (2.8571 E-4 mol)*(39.997 g/mol) = 0.0114 g