Preparation and Properties of Compounds MCQ Questions & Answers in Inorganic Chemistry | Chemistry

The best method for the separation of naphthalene and benzoic acid from their mixture is sublimation because it is applicable for those organic compounds which pass directly from solid to vapour state on heating and vice versa on cooling. In these compounds naphthalene is volatile and benzoic acid is non-volatile due to the formation of dimer via hydrogen bonding ( intermolecular ).

$$\eqalign{ & {\text{Percentage of }}P \cr & = \frac{{62}}{{222}} \times \frac{{wt.\,{\text{of}}\,\,M{g_2}{P_2}{O_7}}}{{wt.\,{\text{of compound}}}} \times 100 \cr & = \frac{{62}}{{222}} \times \frac{{1.332}}{{2.79}} \times 100 \cr & = 13.33\% \cr} $$

The ionic equation for oxidation of Mohr’s salt is $$F{e^{2 + }} \to F{e^{3 + }} + {e^ - }$$
Now $$Eq.$$  of Mohr’s salt $$ = \frac{{392}}{1} = 392$$
Strength = Normality × $$Eq.$$  mass
$$ = \frac{1}{{20}} \times 392 = 19.6g/lit$$
Thus for preparing $$250\,ml$$  of $$\frac{N}{{20}}$$  Mohr’s salt solution, Mohr ’s salt needed $$ = \frac{{19.6}}{{1000}} \times 250 = 4.9\,g$$