Question

Va rog urgent aceasta problema

Answer 1

a) n = 30 mmoli
1 mol = 1000 mmoli

30 mmoli = 0,03 moli HCl
Vs = 0,3 L

C = n/Vs = 0,03/0,3 = 0,1 M

HCl - Acid tare => [HCl] = C = [H₃O⁺] = 10⁻¹M

pH = -lg[H₃O⁺] = -lg 10⁻¹ = 1

b) KOH - baza tare ⇒  [KOH] = C = [OH⁻] = 10⁻² M

pOH = -lg[OH⁻] = -lg 10⁻² = 2
pH+pOH = 14 ⇒ pH = 14-2 = 12

c) C = md/M*Vs(L) = 0,8/40*0,2 = 0,1 M

NaOH - B.T ⇒ [NaOH] = C = [OH⁻] = 10⁻¹M

pOH = -lg[OH⁻]  = -lg 10⁻¹ = 1

pH + pOH = 14 => pH = 13