Molar mass of the salt from $\mathrm{NaBr}, \mathrm{NaNO}_3, \mathrm{KI}$ and $\mathrm{CaF}_2$ which does not evolve coloured vapours on heating with concentrated $\mathrm{H}_2 \mathrm{SO}_4$ is ________ $\mathrm{g} \mathrm{~mol}{ }^{-1}$.
(Molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}: \mathrm{Na}: 23, \mathrm{~N}: 14, \mathrm{~K}: 39, \mathrm{O}: 16, \mathrm{Br}: 80, \mathrm{I}: 127, \mathrm{~F}: 19, \mathrm{Ca}: 40)$$
Answer (integer)
78
Solution
<p>$\mathbf{C a F}_2$ does not evolve any gas with concentrated $\mathrm{H}_2 \mathrm{SO}_4$.</p>
<p>$\mathrm{NaBr} \rightarrow$ evolve $\mathrm{Br}_2$</p>
<p>$\mathrm{NaNO}_3 \rightarrow$ evolve $\mathrm{NO}_2$</p>
<p>$\mathrm{KI} \rightarrow$ evolve $\mathrm{I}_2$</p>
About this question
Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept
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