Previous Year NEET Question- Chemical Bonds

2019:

The correct answer is (A). The C-C bond length in benzene is 1.39 Å, which is shorter than the C-C bond length in ethane (1.54 Å). This is because the pi electrons in benzene delocalize over the entire ring, which results in an increase in the electron density between the carbon atoms and a decrease in the bond strength.

2018:

The correct answer is (B). The N-O bond length in NO2 is 1.21 Å, which is longer than the N-O bond length in NO (1.15 Å). This is because the presence of the second oxygen atom in NO2 increases electron density around the nitrogen atom, which results in an increase in the bond length.

2017:

The correct answer is (A). The C-O bond length in CO2 is 1.16 Å, which is longer than the C-O bond length in CO (1.12 Å). This is because the presence of the second oxygen atom in CO2 pulls electron density away from the carbon atom, which results in an increase in the bond length