NEET Practice Questions (MCQs) with Answers & Solutions

Yellow coloured ferric chloride reacts with hydrogen sulphide to form green coloured ferrous chloride.
In this reaction ferric chloride is reduced and hydrogen sulfide is oxidized.

2FeCl3​+ H2​S âŸ¶  2FeCl2+ 2HCl+ S

The geometry of H2S is angular or bent, with an angle of approximately 92.1°. It has a non-zero dipole moment due to the difference in electronegativity between the hydrogen and sulfur atoms, resulting in a polarized molecule.

acidity of hydride increase down the group, due to increase in bond length

Sulfur Dioxide and Hydrogen Sulfide Reaction, SO2 + H2S = S + H2O

b)

B.P increases down the grp, but due to hydrogen bonding H2O is having highest BP ,where as H₂S is having min B.P 

(a) CuSO⁴_(aq.)$\stackrel{{\mathrm{H}}_2\mathrm{S}\uparrow }{\to }$    2CuS        $\underset{excess}{\overset{\mathrm{KCN}}{\to }}$[Cu(CN)₄]^3-+(CN)2$\uparrow$

                             Black ppr.(M)                  (N)               (O)

(a) 2CrO₄^2-+ 2H⁺$\to$Cr₂O₇^2-+H₂O

     Cr₂O₇^2-+2OH^-$\to$2CrO₄^2-+H₂O

When steam is passed over red hot iron, the reaction that takes place is: 3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g). Iron is oxidized to Fe3O4 (iron(II,III) oxide or magnetite), and hydrogen gas is evolved. This reaction is used in the industrial production of hydrogen gas.

(b) NaCl(s) + K₂Cr₂O₇ + H₂SO₄ (few drops)$\underset{\mathrm{reaction}}{\overset{\mathrm{Non} \mathrm{redox}}{\to }}$CrO₂Cl₂$\uparrow$+H₂O

CrO₂Cl₂ + OH^-_(aq.)$\to$CrO_4(aq)^2-+Cl^-+2H₂O