Question

The right option for the mass of CO₂ produced by heating 20 g of 20% pure limestone is

(Atomic mass of Ca = 40)

[CaCO₃ \(\xrightarrow{1200 K}\) CaO + CO₂]

(1) 1.76 g

(2) 2.64 g

(3) 1.32 g

(4) 1.12 g

Answer 1

Correct option is (1) 1.76 g

Weight of impure limestone = 20 g

Weight of pure limestone (CaCO₃) = 20% of 20 g

\(= \frac{20}{100} \times20\)

\(= 4g\)

\(n_{CaCO_3} = \frac 4{100} = 0.04\)

\(\underset{n = 0.04}{CaCO_3 }\to CaO +\underset{n = 0.04} {CO_2}\)

\(n_{CO_2} = 0.04\)

\(W_{CO_2} = 0.04 \times 44\)

\(= 1.76 g\)