Amphoteric oxide from aluminum matches the reaction sequence

Steps:

• Y burns in O₂ to form a white solid oxide.
• White solid reacts with HCl(aq) to form a soluble salt.
• Soluble salt with NaOH(aq) forms a white precipitate of hydroxide.
• White precipitate dissolves in excess NaOH(aq) to form a solution.

Why C is correct:

• Aluminum forms Al₂O₃ (white solid) on burning; Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O (soluble); AlCl₃ + 3NaOH → Al(OH)₃ (white ppt) + 3NaCl; Al(OH)₃ + NaOH → Na[Al(OH)₄] (soluble), showing amphoteric behavior.

Why the others are wrong:

• A. Na: Na₂O + HCl forms soluble NaCl; no precipitate with NaOH.
• B. Mg: MgO + HCl forms MgCl₂; Mg(OH)₂ precipitate insoluble in excess NaOH.
• D. P: P₄O₁₀ reacts as acidic oxide, not forming amphoteric hydroxide precipitate that redissolves in NaOH.

Final answer: C