The reactions of carboxylic acids

This chapter includes ionic reactions. The hydronium ion $H_3O^+$ is simplified by $H^+$

Reactions with hydroxides (neutralisations)

$H^+$ $+$ $OH^-$ $\rightarrow$ $ H_2O$

Examples Reaction between formic acid and sodium hydroxide: $HCOO^-$ $+$ $H^+$ $+$ $Na^+$ $+$ $OH^-$ $\rightarrow$ $ HCOO^-$ $+$ $Na^+$ $+$ $H_2O$ Product is a solution of sodium formiate Reaction between acetic acid and iron(III) hydroxide (insoluble): $3CH_3COO^-$ $+$ $3H^+$ $+$ $Fe^{3+}(OH^-)_3$ $\rightarrow $ $3CH_3COO^-$ $+$ $Fe^{3+}$ $+$ $3H_2O$ Product is a solution of iron(III) acetate

Reaction with oxides

$2H^++O^{2-}\rightarrow H_2O$

Examples Reaction between acetic acid and lead(II) oxide (insoluble): $2CH_3COO^-$ $+$ $2H^+$ $+$ $Pb^{2+}O^{2-}$ $\rightarrow$ $2CH_3COO^-$ $+$ $Pb^{2+}$ $+$ $H_2O$ Product is a solution of lead(II) acetate

Reactions with carbonates and hydrogencarbonates

$H^++HCO_3^-\rightarrow H_2O+CO_2$ $2H^+$ $+$ $CO_3^{2-}$ $\rightarrow$ $ H_2O$ $+$ $CO_2$

Example Reaction between formic acid sodium hydrogencarbonate: $HCOO^-$ $+$ $H^+$ $+$ $Na^+$ $+$ $HCO_3^-$ $\rightarrow$ $ HCOO^-$ $+$ $Na^+$ $+$ $H_2O$ $ +$ $CO_2$ Product is a solution of sodium formiate, carbon dioxide(g) is liberated. Reaction between acetic acid and calcium hydroxide (insoluble): $2CH_3COO^-$ $+$ $2H^+$ $+$ $Ca^{2+}(OH^-)_2$ $\rightarrow$ $2CH_3COO^-$ $+$ $Ca^{2+}$ $+$ $2H_2O$ $+$ $2CO_2$ Product is a solution of calcium acetate, carbon dioxide(g) is liberated.

Reaction with non-noble metals (redox reactions)

$2H^+$ $+$ $Mg$ $\rightarrow$ $ H_2$ $+$ $Mg^{2+}$ $2H^+$ $+$ $Zn$ $\rightarrow$ $ H_2$ $+$ $Zn^{2+}$ $2H^+$ $+$ $Fe$ $\rightarrow $ $H_2$ $+$ $Fe^{2+}$

Example Reaction between acetic acid and iron: $2CH_3COO^-$ $+$ $2H^+$ $+$ $Fe$ $\rightarrow$ $2CH_3COO^-$ $+$ $Fe^{2+}$ $+$ $H_2$ Product is a solution of iron(II)acetate, hydrogen(g) is liberated.