Chemistry MCQs for NEET — Practice Questions with Answers

(c) The C-C bond length is maximum for single bond, so butane have largest C-C bond length because it contains carbon-carbon single bond.

The acidic strength of carboxylic acids decreases with an increase in the size of the alkyl group. This is because the larger alkyl groups have a greater electron-releasing or electron-donating effect, which decreases the polarity of the O-H bond, making it less acidic. Therefore, the correct decreasing order of acidic strength is: methanoic acid > ethanoic acid > propanoic acid > butanoic acid.

As the electronegativity of the atom at which -ve charge is present, the stability of the carbanion also increases. The order is

$\mathrm{CH}\equiv {\mathrm{C}}^{-}>{\mathrm{CH}}_2={\mathrm{CH}}^{-}>{\mathrm{CH}}_3^{-}$

Addition of Br₂ in alkene is an example of anti addition. Trans alkene on anti addition give meso compound.

Due to ortho effect, ortho derivative is most acidic. If electron withdrawing group like -NO₂ is present in ring then order of acidity is -o>p->m-

In Ph-Cl, due to resonance C-Cl bond has partial double bond character and have minimum bond length.

The configuration in a compound is independent of its physical properties (optical activity)

Both +I and –I effect decreases with distance.

${\mathrm{Na}}_2\mathrm{S}+\underset{\mathrm{sodium} \mathrm{nitroprusside}}{{\mathrm{Na}}_2\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_5\left(\mathrm{NO}\right)\right]}\to \underset{\mathrm{violet} \mathrm{or} \mathrm{purple} \mathrm{colour}}{{\mathrm{Na}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_5\mathrm{NOS}\right]}$