M1: "$H_{3}BO_{3}$ has 3 acidic H atoms." CORRECT: $H_{3}BO_{3}$ is monobasic. Only 1 $H^{+}$ is released per molecule via Lewis acid mechanism.

M2: "Boric acid donates protons just like HCl." CORRECT: $H_{3}BO_{3}$ is a Lewis acid (accepts $OH^{-}$), not a Bronsted acid ($H^{+}$ donor).

M3: "$H_{3}PO_{3}$ is tribasic because it has 3 H atoms." CORRECT: $H_{3}PO_{3}$ is DIBASIC (2 P-OH bonds). Total H count ≠ basicity.

M4: "Black phosphorus is rare and unimportant." CORRECT: Black P is the most thermodynamically stable allotrope. It is also a layered semiconductor, researched extensively for transistors.

M5: "The Haber process uses Pt catalyst." CORRECT: Haber process uses finely divided Fe. Pt/Rh is used in Ostwald Step 1.

M6: "All steps of the Ostwald process need a catalyst." CORRECT: Only Step 1 ($NH_{3}$ oxidation) needs Pt-Rh. Step 2 and Step 3 are uncatalysed.

M7: "$N_{2}O_{3}$ and $NO_{2}$ are neutral oxides." CORRECT: Both are acidic. Only $N_{2}O$ and NO are neutral nitrogen oxides.

M8: "$NO_{2}$ is diamagnetic." CORRECT: $NO_{2}$ has 17 electrons (odd) — it is paramagnetic with 1 unpaired electron.

M9: "Diborane has a B-B bond." CORRECT: There is NO direct B-B bond in $B_{2}H_{6}$. The two B atoms are linked only through the two bridging H atoms (via 3c-2e bonds).

M10: "In $PCl_{5}$, all bonds are equal in length." CORRECT: Axial P-Cl bonds (~214 pm) are longer than equatorial P-Cl bonds (~202 pm) due to greater 90° repulsion on axial bonds.

M11: "$NCl_{5}$ exists like $PCl_{5}$." CORRECT: $NCl_{5}$ cannot exist because N has no d-orbitals in its valence shell (n=2) for $sp^{3}$d hybridization. P has 3d orbitals available.

M12: "$AlCl_{3}$ is a simple monomer in all conditions." CORRECT: $AlCl_{3}$ exists as dimer $Al_{2}Cl_{6}$ in solid state and in non-polar solvents, though it dissociates to monomer in polar solvents and at very high temperatures in gas phase.

M13: "High pressure is not commercially feasible for Haber — so low pressure is used." CORRECT: Approximately 200 atm IS used in the Haber process. This is commercially viable with modern engineering.

M14: "White phosphorus is stored in air under controlled conditions." CORRECT: White P must be stored under water (not air), because it ignites spontaneously in air.

M15: "$CO_{2}$ fire extinguishers work on all types of fires including metal fires." CORRECT: $CO_{2}$ extinguishers must NEVER be used on Mg fires. Burning Mg reduces $CO_{2}$ (2Mg + $CO_{2}$ → 2MgO + C), potentially spreading the fire.