TEORI ASAM BASA
Teori Asam-Basa Arrhenius
ASAM
zat yang melepas ion \(\ce{H+}\) dalam pelarut air
Contoh:
\(\ce{HCl (aq) -> H+ (aq) + Cl- (aq) }\)
\(\ce{H2S (g) -> 2H+ (aq) + S^{2-} (aq)}\)
BASA
zat yang melepas ion \(\ce{OH-}\) dalam pelarut air
Contoh:
\(\ce{NaOH (aq) -> Na+ (aq) + OH- (aq)}\)
\(\ce{Mg(OH)2 (aq) -> Mg^{2+} (aq) + 2OH- (aq)}\)
Teori Asam-Basa Bronsted-Lowry
ASAM
zat yang melepas 1 proton
(proton dilepas dalam bentuk ion \(\ce{H+}\))
\(\ce{Asam <=> Proton + Basa Konjugasi}\)
BASA
zat yang menerima 1 proton
(proton diterima dalam bentuk ion \(\ce{H+}\))
\(\ce{Basa + Proton <=> Asam Konjugasi}\)
Contoh-contoh
\(\ce{$\underset {\text{Asam}} {\ce{HF}}$ + $\underset{\text{Basa}}{\ce{NH3}}$ <=> $\underset {\text{Basa konjugasi}} {\ce{F-}}$ + $\underset{\text{Asam konjugasi}}{\ce{NH4+}}$}\)
\(\ce{$\underset {\text{Asam}} {\ce{H2SO4}}$ + $\underset{\text{Basa}}{\ce{CO3^{2-}}}$ <=> $\underset {\text{Basa konjugasi}} {\ce{HSO4^{-}}}$ + $\underset{\text{Asam konjugasi}}{\ce{HCO3-}}$}\)
\(\ce{$\underset {\text{Asam}} {\ce{HSO4-}}$ + $\underset{\text{Basa}}{\ce{HS^{-}}}$ <=> $\underset {\text{Basa konjugasi}} {\ce{SO4^{2-}}}$ + $\underset{\text{Asam konjugasi}}{\ce{H2S}}$}\)
\(\ce{$\underset {\text{Asam}} {\ce{HF}}$ <=> $\underset{\text{Proton}}{\ce{H+}}$ + $\underset{\text{Basa konjugasi}}{\ce{F-}}$}\)
\(\ce{$\underset {\text{Asam}} {\ce{H2SO4}}$ <=> $\underset{\text{Proton}}{\ce{H+}}$ + $\underset{\text{Basa konjugasi}}{\ce{HSO4^{-}}}$}\)
\(\ce{$\underset {\text{Asam}} {\ce{HSO4-}}$ <=> $\underset{\text{Proton}}{\ce{H+}}$ + $\underset{\text{Basa konjugasi}}{\ce{SO4^{2-}}}$}\)
\(\ce{$\underset {\text{Basa}} {\ce{NH3}}$ + $\underset{\text{Proton}}{\ce{H+}}$ <=> $\underset {\text{Asam konjugasi}} {\ce{NH4+}}$}\)
\(\ce{$\underset {\text{Basa}} {\ce{CO3^{2-}}}$ + $\underset{\text{Proton}}{\ce{H+}}$ <=> $\underset {\text{Asam konjugasi}} {\ce{HCO3-}}$}\)
\(\ce{$\underset {\text{Basa}} {\ce{HS^{-}}}$ + $\underset{\text{Proton}}{\ce{H+}}$ <=> $\underset {\text{Asam konjugasi}} {\ce{H2S}}$}\)
Teori Asam-Basa Lewis
Teori asam-basa Lewis menyatakan bahwa:
- Asam adalah zat yang menerima pasangan elektron
- Basa adalah donor pasangan elektron
Pada reaksi:
\(\ce{NH3 (g) + HCl (aq) -> NH4Cl(aq)}\)
Pasangan elektron bebas yang dimiliki atom \(\ce{N}\) diberikan pada atom \(\ce{H}\)
\(\ce{NH3}\) sebagai donor elektron adalah basa
\(\ce{HCl}\) sebagai akseptor elektron adalah asam
Zat Amfoter
Zat amfoter adalah zat yang dapat bertindak sebagai asam dan basa.
\(\ce{H2PO4-}\) sebagai asam
\(\ce{$\underset {\text{Asam}} {\ce{H2PO4-}}$ + $\underset{\text{Basa}}{\ce{OH-}}$ <=> $\underset {\text{Basa konjugasi}} {\ce{HPO4^{2-}}}$ + $\underset{\text{Asam konjugasi}}{\ce{H2O}}$}\)
\(\ce{H2PO4-}\) sebagai basa
\(\ce{$\underset {\text{Basa}} {\ce{H2PO4-}}$ + $\underset{\text{Asam}}{\ce{HBr}}$ <=> $\underset {\text{Asam konjugasi}} {\ce{H3PO4}}$ + $\underset{\text{Basa konjugasi}}{\ce{Br-}}$}\)
\(\ce{H2O}\) sebagai asam dan basa
\(\ce{$\underset {\text{Asam}} {\ce{H2O}}$ + $\underset {\text{Basa}} {\ce{H2O}}$ <=> $\underset {\text{Basa konjugasi}} {\ce{OH-}}$ + $\underset {\text{Asam konjugasi}} {\ce{H3O+}}$}\)
\(\ce{NH3}\) sebagai asam dan basa
\(\ce{$\underset {\text{Asam}} {\ce{NH3}}$ + $\underset {\text{Basa}} {\ce{NH3}}$ <=> $\underset {\text{Basa konjugasi}} {\ce{NH4+}}$ + $\underset {\text{Asam konjugasi}} {\ce{NH2-}}$}\)
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