Question

Why does a buffer solution resist the change in pH? Please provide three examples.

Answer 1

Question #47788, Chemistry, Inorganic Chemistry

Why does a buffer solution resist the change in pH? Please provide three examples.

Answer:

Buffer solutions - solutions that this little change pH by dilution with water or addition of small amounts of strong acids or bases.

Buffering properties of the solution mixture are weak acids or weak bases and their salts and mixtures of two acid salts or acid salts and secondary polybasic acids.

For example:

1) acetate buffer (CH₃COOH + CH₃COONa)

$$\mathrm{CH_3COOH} + \mathrm{CH_3COO^-} \xrightarrow{H^+} \mathrm{CH_3COO^-} + \mathrm{H^+} \leftrightarrow \mathrm{CH_3COOH};$$ $$\mathrm{CH_3COOH} + \mathrm{CH_3COO^-} \xrightarrow{OH^-} \mathrm{CH_3COOH} + \mathrm{OH^-} \leftrightarrow \mathrm{CH_3COO^-} + \mathrm{H_2O}$$

2) $(\mathrm{Na_2CO_3} + \mathrm{NaHCO_3})$

$$\mathrm{CO_3^{2-}} + \mathrm{HCO_3^-} \xrightarrow{H^+} \mathrm{CO_3^{2-}} + \mathrm{H^+} \leftrightarrow \mathrm{HCO_3^-}$$ $$\mathrm{CO_3^{2-}} + \mathrm{HCO_3^-} \xrightarrow{OH^-} \mathrm{HCO_3^-} + \mathrm{OH^-} \leftrightarrow \mathrm{CO_3^{2-}} + \mathrm{H_2O}$$

3) $\mathrm{Na_2HPO_4} + \mathrm{Na_2HPO_4}$

$$\mathrm{HPO_4^{2-}} + \mathrm{H_2PO_4^{2-}} \xrightarrow{H^+} \mathrm{HPO_4^{2-}} + \mathrm{H^+} \leftrightarrow \mathrm{H_2PO_4^{2-}}$$ $$\mathrm{HPO_4^{2-}} + \mathrm{H_2PO_4^{2-}} \xrightarrow{OH^-} \mathrm{H_2PO_4^{2-}} + \mathrm{OH^-} \leftrightarrow \mathrm{H_2PO_4^{2-}} + \mathrm{H_2O}$$

https://www.AssignmentExpert.com