V.
[HO] = 10⁻⁶ mol/L
stim ca pOH = -lg[HO-] = -lg10⁻⁶
= -(-6) = 6
stim ca pOH + pH = 14 => pH = 14-6 = 8
VI.
a)
HClO4 + H2O <==> (ClO4)⁻ + H3O⁺
b)
md = 20,1 g, Vs = 200 mL = 0,2 L
stim ca Cm = md/miuxVs, miu.HClO4 = 100,5 g/mol
=> Cm = 20,1/100,5x0,2 = 1 mol/L
fiind un acid tare, acesta ionizeaza complet in solutie apoasa si Cm.acid = [HO+] = 1 mol/L
c)
pH = -lg[H3O+] = -lg1 = 0
