Question

The set of amphoteric oxides among \(ZnO, Tl_2O_3, In_2O_3, B_2O_3, PbO, SnO_2\) is

• A. \(ZnO, Tl_2O_3, PbO\)
• B. \(ZnO, PbO, SnO_2\)
• C. \(ZnO, In_2O_3, SnO_2\)
• D. \(ZnO, In_2O_3, PbO\)

Hint:

Common amphoteric oxides include: \[ ZnO,\ Al_2O_3,\ PbO,\ SnO_2,\ BeO \] These react with both acids and bases.

Answer 1

The Correct Option is B

Step 1: Define amphoteric oxides.
Amphoteric oxides react with both strong acids and strong bases to form salt and water. They exhibit dual acid-base character depending on the reaction partner. The classic test: an oxide is amphoteric if it dissolves in both $ HCl $ and $ NaOH $.
Step 2: Analyze ZnO.
Zinc oxide is the textbook example of an amphoteric oxide. It reacts with acid: $ ZnO + 2HCl \to ZnCl_2 + H_2O $, and with base: $ ZnO + 2NaOH \to Na_2ZnO_2 + H_2O $. Confirmed: amphoteric.
Step 3: Analyze PbO and SnO2.
Lead(II) oxide $ PbO $ reacts with both $ HCl $ (to give $ PbCl_2 $) and with $ NaOH $ (to give plumbite $ Na_2PbO_2 $) - amphoteric. Tin(IV) oxide $ SnO_2 $ similarly reacts with strong base to give stannate ions and with acid to give $ Sn^{4+} $ salts - amphoteric.
Step 4: Analyze Tl2O3, In2O3, B2O3.
$ Tl_2O_3 $: thallium(III) oxide is predominantly basic, not amphoteric. $ In_2O_3 $: indium(III) oxide is basic in character and does not readily react with bases. $ B_2O_3 $: boron trioxide is acidic (not amphoteric).
Step 5: Identify the correct set.
The amphoteric oxides from the given list are: $ ZnO $, $ PbO $, and $ SnO_2 $.
Step 6: Final answer.
\[ \boxed{ZnO,\ PbO,\ SnO_2} \]