Trap 1 — Phosphorus Oxoacid Basicity:

• ERROR: "$H_{3}PO_{2}$ is tribasic because it has 3 hydrogen atoms."
• CORRECT: Basicity = P-OH bond count, NOT total H count. $H_{3}PO_{2}$ has 1 P-OH → monobasic. P-H bonds do NOT ionize.

Trap 2 — Boric Acid Acidity Type:

• ERROR: "$H_{3}BO_{3}$ is a Bronsted acid and donates $H^{+}$ directly."
• CORRECT: $H_{3}BO_{3}$ is a Lewis acid. Boron accepts $OH^{-}$ from water. The $H^{+}$ in solution comes from water, not $H_{3}BO_{3}$.

Trap 3 — Haber vs Ostwald Catalyst:

• ERROR: Mixing up catalysts — using Pt/Rh for Haber or Fe for Ostwald Step 1.
• CORRECT: Haber = Finely divided Fe. Ostwald Step 1 = Pt-Rh gauze at 500°C. Step 2 = no catalyst.

Trap 4 — Haber Temperature:

• ERROR: "Low temperature maximises both rate AND yield."
• CORRECT: Low temperature maximises yield (exothermic reaction) but slows rate. 450°C is a COMPROMISE. You sacrifice some yield for commercially acceptable rate.

Trap 5 — Diborane Bond Type:

• ERROR: "$B_{2}H_{6}$ contains 3-centre-4-electron bonds."
• CORRECT: Bridging B-H-B bonds in $B_{2}H_{6}$ are 3-centre-2-ELECTRON (3c-2e) bonds — electron-deficient, not 3c-4e.

Trap 6 — $NO_{2}$ Dimerisation Direction:

• ERROR: "High temperature favours $N_{2}O_{4}$ formation."
• CORRECT: 2$NO_{2}$ ⇌ $N_{2}O_{4}$ is exothermic. LOW temperature favours $N_{2}O_{4}$ (colourless). High temperature gives more $NO_{2}$ (brown). Brown colour of concentrated $HNO_{3}$ is from dissolved $NO_{2}$.

Trap 7 — Neutral vs Acidic Nitrogen Oxides:

• ERROR: Classifying $N_{2}O_{3}$ or $NO_{2}$ as neutral because N-O compounds "look" neutral.
• CORRECT: Only $N_{2}O$ (+1) and NO (+2) are neutral. ALL oxides with N in +3 or above are acidic.

Trap 8 — Black vs White Phosphorus Stability:

• ERROR: "White phosphorus is most stable because it is the common laboratory form."
• CORRECT: Black phosphorus is thermodynamically most stable. White P is the LEAST stable, most reactive, and most toxic allotrope.