JEE Main · 2025 · 04 Apr 2025 · Shift 2 · Some Basic Concepts of Chemistry

The amount of calcium oxide produced on heating 150 kg limestone (75% pure) is ______ kg.
(Nearest integer)
Given: Molar mass (in

g mol^{- 1}

) of Ca-40, O-16, C-12

Answer: 63

Solution

On heating, limestone decomposes as

CaC O_{3} \to CaO + C O_{2}

. The pure calcium carbonate present is

\frac{150 \times 75}{100} = 112.5 kg

. With molar masses of

100 g mo l^{- 1}

for

CaC O_{3}

and

56 g mo l^{- 1}

for

CaO

, every

100

parts of carbonate give

56

parts of oxide, so the calcium oxide obtained is

112.5 \times \frac{56}{100} = 63 kg

. The mass of calcium oxide produced is

63 kg

JEE Main · 2025 · 04 Apr 2025 · Shift 2 · Integer answer