The curve above represents the solubility curve of \(KClO _{3}\). The number of moles of \(KClO _{3}\) crystals produced by cooling \(200 cm ^{3}\) of a saturated solution of the salt from \(65^{\circ} C\) to \(25^{\circ} C\) is ____________
A. \(6.30 mol\) B. \(1.26\) mole C. \(0.63\) mole D. \(7.30\) mole
Correct Answer: B
Explanation
From the graph, solubility of \(KClO _{3}\) at \(65^{\circ} C \Longrightarrow 6 moldm ^{-3}\), that at \(25^{\circ} C =1\) moldm \(^{-3}\) Mole present in solution at \(65^{\circ} C\) \(=\left(\frac{6 \times 20}{100}\right) \Rightarrow 1.2\) mole Mole present in solution at \(25^{\circ} C\) \begin{aligned} &=\left(\frac{1 \times 200}{1000}\right) \Rightarrow 0.2 \text { mole } \\ &\text { Precipitate }=1.2 mole -0.2 \text { mole } \\ &\Rightarrow \text { 1mole } \end{aligned}