NEET Practice Questions (MCQs) with Answers & Solutions

(a) It is an assumption, because only one oxygen comes out from H₂O₂

(a) Percent conc. of H₂O₂= $\frac{17}{56}\times$ volume conc. of H₂O₂

        =$\frac{17}{56}\times 10=3\% \mathrm{app}.$

or 

2H2O2 gives 2H2O + O2..
So in 22.4 lit of O2 have 68 gm of H2O2....10 lit of O2 have
10×68÷22.4=30 g/l, means 3%

(a) H₂O₂ acts both as reductant and oxidant.

$$\begin{gathered} {\left({\mathrm{O}}^{-1}\right)}_2\stackrel{ }{\to }{\left(\mathrm{O}°\right)}_2 + 2e \\ \mathrm{Reductant} \\ {\left({\mathrm{O}}^{-1}\right)}_2 + 2\mathrm{e} \stackrel{ }{\to } 2{\mathrm{O}}^{-2} \\ \mathrm{Oxidant} \end{gathered}$$

(d) ${\mathrm{TiO}}_2 + {\mathrm{H}}_2{\mathrm{O}}_2 \stackrel{ }{\to }{\mathrm{H}}_2{\mathrm{TiO}}_4 \left(\mathrm{orange}\right)$

(a) H₂O₂ is di-basic acid and thus, less stable in basic medium.

(c) 

The maximum density of water occurs at 4 °C because, at this temperature two opposing effects are in balance. Explanation: In ice, the water molecules are in a crystal lattice that has a lot of empty space. When the ice melts to liquid water, the structure collapses and the density of the liquid increases.

(d) Atomic hydrogen is obtained by passing ordinary hydrogen through an electric arc.

              ${\mathrm{H}}_2\underset{\mathrm{arc}, 200°\mathrm{C}}{\overset{\mathrm{Electric}}{\to }}2\mathrm{H}; ∆H=104.5 \mathrm{kcal} {\mathrm{mol}}^{-1}$

(a) Permutit are complex inorganic salts like sodium alumino silicate $\left({\mathrm{Na}}_2{\mathrm{Al}}_2{\mathrm{SiO}}_3·x{\mathrm{H}}_2\mathrm{O}\right) \mathrm{or} \mathrm{zeolite} \left({\mathrm{Na}}_2\mathrm{Z}\right) \mathrm{where} \mathrm{Z} \mathrm{is} {\mathrm{Al}}_2{\mathrm{SiO}}_3·{\mathrm{xH}}_2\mathrm{O}$