Chemistry Hub

Which of the following is not paramagnetic ?
(a) N
(b) CO
(c) O-
(d) NO

Oxygen molecule is
(a) diamagnetic with no unpaired electrons
(b) diamagnetic with two unpaired electrons
(c) paramagnetic with two unpaired electrons
(d) paramagnetic with no unpaired electrons

Number of ʌ bonds in naphthalene are
(a) 6
(b) 3
(c) 4
(d) 5

Which of the following molecule is paramagnetic?
(a) CO2
(b) SO2
(c) NO
(d) H2O

N2 and O2 are converted into monocations, N and O respectively. Which of the following statements is wrong?
(a) In N , N - N bond weakens
(b) In O , the O - O bond order increases
(c) In O , paramagnetism decreases
(d) N becomes diamagnetic

Chemical bond implies
(a) repulsion
(b) attraction
(c) attraction and repulsion balanced at a particular distance
(d) attraction and repulsion

The states of hybridisation of boron and oxygen atoms in boric acid (H3BO3) are respectively
(a) sp3 and sp2
(b) sp2 and sp3
(c) sp2 and sp2
(d) sp3 and sp3

Which does not show resonance ?
(a) Benzene
(b) Aniline
(c) Ethylamine
(d) Toluene

Polarity in a molecule and hence the dipole moment depends
primarily on electronegativity of the constituent atoms and
shape of a molecule. Which of the following has the highest
dipole moment?
(a) CO2
(b) HI
(c) H2O
(d) SO2

Sodium chloride is an ionic compound whereas hydrogen
chloride is mainly covalent because
(a) sodium is less reactive
(b) hydrogen is non-metal
(c) hydrogen chloride is a gas
(d) electronegativity difference in the case of hydrogen
and chlorine is less than 2.1.

Which one of the following molecules will have unequal
M – F bond lengths ?
(a) NF3
(b) BF3
(c) PF5
(d) SF4