Group 13 Reactions

Diborane hydrolysis: $B_2H_6 + 6H_2O \rightarrow 2H_3BO_3 + 6H_2$

Boric acid Lewis acid reaction (key mechanism): $H_3BO_3 + H_2O \rightarrow [B(OH)_4]^- + H^+$

Borax hydrolysis in water (alkaline): $Na_2B_4O_7 + 7H_2O \rightarrow 2NaOH + 4H_3BO_3$

Borax bead test (heating): $Na_2B_4O_7 \xrightarrow{\Delta} 2NaBO_2 + B_2O_3$

Group 14 Reactions

Magnesium burning in $CO_{2}$: $2Mg + CO_2 \rightarrow 2MgO + C$

$CO_{2}$ acidic oxide: $CO_2 + H_2O \rightarrow H_2CO_3$

Group 15 — Haber Process

$N_2(g) + 3H_2(g) \underset{200\,\text{atm}}{\overset{Fe,\;450°C}{\rightleftharpoons}} 2NH_3(g) \qquad \Delta H = -92\;\text{kJ mol}^{-1}$

Group 15 — Ostwald Process

Step 1 (catalytic oxidation): $4NH_3 + 5O_2 \xrightarrow{\text{Pt/Rh, 500°C}} 4NO + 6H_2O$

Step 2 (uncatalysed oxidation): $2NO + O_2 \rightarrow 2NO_2$

Step 3 (absorption): $3NO_2 + H_2O \rightarrow 2HNO_3 + NO \uparrow \text{(recycled)}$

Nitrogen Oxide Anhydride Reactions

$N_2O_3 + H_2O \rightarrow 2HNO_2$

$N_2O_5 + H_2O \rightarrow 2HNO_3$

Phosphorus Oxoacid Ionization (dibasic example)

$H_3PO_3 \rightleftharpoons H^+ + H_2PO_3^- \quad (K_{a1})$

$H_2PO_3^- \rightleftharpoons H^+ + HPO_3^{2-} \quad (K_{a2})$

(Third H does NOT ionize — it is a P-H bond)