Chemistry MCQs for NEET — Practice Questions with Answers

(1)

Hydrofluoric acid won't eat through plastic

The boiling points of $HF,HCl,HBrandHI$ follow the order $HF>HI>HBr>HCl$.
HF is hydrogen bonded, thus has highest boiling point, and it is liquid at or below 19oC. The remaining hydrogen halides are gaseous and their boiling points depend on the van der waal's forces. Larger the size (or molecular mass), greater are the van der Waal's forces, hence higher is the boiling point.

Cl has 7 valance electron and 3 is bonded ,so 4 electron is left. hence its 2 pair.

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)