A metilamina
(CH3 NH2) é um derivado da base fraca do amoníaco. Escreva a equação para a ionização da metilamina na água, encontrar o pH de uma solução de
CH3 NH2 a
3,75 mol / L .
(Kb=4,37 times 10^-4 a
25^circ C) .
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Uma solução-tampão é preparada a partir de
6,4 g de
NH4 NO3 e
0,10 L de solução aquosa
0,080 mol / L de
NH4 OH . Sendo assim, determine: Dados:(H=1;
N=14 ; O=16)
a) o pH desta solução;
b) o pH após adição de 700 mL de água destilada à solução-tampão, justificando com os cálculos. Dados:
Kb=1,8 cdot 10^-5