Question

Ce cantitate de NaOH vor contine 500 ml solutie cu pH= 1 1.
Ce volum de solutie 0,5 M de HCI va neutraliza această solutie?

Answer 1

pH+pOH = 14 ⇒ pOH = 14-11 = 3 

NaOH - B.T ⇒ [NaOH] = C = [OH⁻] = $10^{-pOH}$ = 10⁻³ M

C = n/Vs ⇒ n = C*Vs = 10⁻³×0,5 = 5×10⁻⁴ moli NaOH

m NaOH = 40×5×10⁻⁴ = 0,02g

NaOH + HCl ⇒ NaCl + H₂O

n NaOH = nHCl = 5×10⁻⁴ moli

C = n/Vs ⇒ Vs = n/C = 5×10⁻⁴/5×10⁻¹ = 10⁻³ L = 1mL sol. HCl