NEET Practice Questions (MCQs) with Answers & Solutions

(a)

When aquous sodium chloride undergo electrolysis in presence of platinum electrodes, the reaction is follows-
NaCl ---> Na+ + Cl-
H20 ---> H+ + OH-

At anode, Cl- ions are discharged in preference to OH- ions.
Cl- ---> (1/2)Cl2 + e-

At cathode, H+ ions are discharged in preference to Na+ ions.
H+ + e- ---> (1/2)H2

Overall reaction is -
NaCl + H20 ---> Na+ + OH- + (1/2)H2 + (1/2)Cl2

(b) ${\mathrm{O}}_2^{-1}$ can be oxidised to O₂ and can be reduced to O^-2.

(a) ${\mathrm{MNO}}_3 \stackrel{ ∆ }{\to } {\mathrm{MNO}}_2 + \frac{1}{2}{\mathrm{O}}_2$

(a) The basic character of alkali metal hydroxides increases down the group.

(a) Indian saltpetre is KNO₃.

(d) Na₂CO₃ is thermally stable.

(c) It is sodium ammonium hydrogen phosphate.

(b) K is used as fertilizer (NPK) for nutrition of plants.

Density of potasium is less than sodium due to anomolous increase in size