Easy INTEGER +4 / -1 PYQ · JEE Mains 2025

The amount of calcium oxide produced on heating 150 kg limestone ( $75 \%$ pure) is _________ kg. (Nearest integer)

Given: Molar mass (in $\mathrm{g} \mathrm{mol}^{-1}$ ) of Ca-40, O-16, C-12

Answer (integer) 63

Solution

<p>$$\begin{aligned} & \mathrm{CaCO}_3 \rightarrow \mathrm{CaO}+\mathrm{CO}_2 \\ & \text { mass of } \mathrm{CaCO}_3=\frac{150 \times 75}{100}=112.5 \mathrm{~kg} \\ & =112500 \mathrm{~g} \\ & \mathrm{n}_{\mathrm{CaCO}_3}=1125 \end{aligned}$$</p> <p>$$\begin{aligned} & \text { So moles of } \mathrm{CaO}=1125 \\ & \qquad \text { mass of } \mathrm{CaO}=\frac{1125 \times 56}{1000}=63 \mathrm{~kg} \\ & \text { Correct answer } \Rightarrow 63 \end{aligned}$$</p>

About this question

Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept

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