Practical Chemistry Question 9
Question 9 - 2024 (31 Jan Shift 1)
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 ________ $\mathrm{gmol}^{-1}$, (Molar mass in $\mathrm{gmol}^{-1}: \mathrm{Na}: 23, \mathrm{~N}: 14, \mathrm{~K}: 39$, $\mathrm{O}: 16, \mathrm{Br}: 80, \mathrm{I}: 127, \mathrm{~F}: 19, \mathrm{Ca}: 40$)
Show Answer
Answer (78)
Solution
$\mathrm{CaF}{2}$ does not evolve any gas with concentrated $\mathrm{H}{2} \mathrm{SO}_{4}$.
$\mathrm{NaBr} \rightarrow$ evolve $\mathrm{Br}_{2}$
$\mathrm{NaNO}{3} \rightarrow$ evolve $\mathrm{NO}{2}$
$\mathrm{KI} \rightarrow$ evolve $\mathrm{I}_{2}$
