How many grams of residue is obtained by heating 2.76 g of silver carbonate? (Given : Molar mass of $\mathrm{C}, \mathrm{O}$ and Ag are 12, 16 and $108 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively)

JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Some Basic Concepts of Chemistry

How many grams of residue is obtained by heating 2.76 g of silver carbonate?
(Given : Molar mass of

C, O

and Ag are 12, 16 and

108 g mol^{- 1}

respectively)

Answer: (B)

Silver carbonate decomposes on strong heating, by way of the oxide, to the metal, the overall change being

A g_{2} C O_{3} \to 2 Ag + C O_{2} + \frac{1}{2} O_{2}

, so the residue left behind is metallic silver. The molar mass of

A g_{2} C O_{3}

2 (108) + 12 + 3 (16) = 276 g mo l^{- 1}

, and

\frac{2.76}{276} = 0.01 mol

of it yields

0.02 mol

of silver. The mass of the residue is

0.02 \times 108 = 2.16 g

JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Single correct option