Among H₂S, H₂O, NF₃, NH₃ and CHCl₃, identify the molecule (X) with lowest dipole moment value. The number of lone pairs of electrons present on the central atom of the molecule (X) is :

Among H₂S, H₂O, NF₃, NH₃ and CHCl₃ identify the molecule with lowest dipole moment

Q. Among H₂S, H₂O, NF₃, NH₃ and CHCl₃, identify the molecule (X) with lowest dipole moment value. The number of lone pairs of electrons present on the central atom of the molecule (X) is :

A. 3

B. 2

C. 0

D. 1

Correct Answer: 1

Explanation

Dipole moment depends on both electronegativity difference and molecular geometry. Among the given molecules, NF₃ has the lowest dipole moment because the N–F bond dipoles oppose the direction of the lone pair dipole on nitrogen.

Due to this cancellation effect, NF₃ has a smaller net dipole moment than NH₃, H₂O, H₂S and CHCl₃.

In NF₃, the central atom nitrogen has one lone pair of electrons.

Hence, the required number of lone pairs on the central atom is 1.

Related JEE Main Questions

Two masses m and 2 m are connected by a light string going over a pulley (disc) of mass 30 m with radius r = 0.1 m. The pulley is mounted in a vertical plane and it is free to rotate about its axis. The 2 m mass is released from rest and its speed when it has descended through a height of 3.6 m is ____ m/s.

A cylindrical conductor of length 2 m and area of cross-section 0.2 mm² carries an electric current of 1.6 A when its ends are connected to a 2 V battery. Mobility of electrons in the conductor is α × 10⁻³ m²/V·s. The value of α is :

A capacitor P with capacitance 10 × 10⁻⁶ F is fully charged with a potential difference of 6.0 V and disconnected from the battery. The charged capacitor P is connected across another capacitor Q with capacitance 20 × 10⁻⁶ F. The charge on capacitor Q when equilibrium is established will be α × 10⁻⁵ C (assume capacitor Q does not have any charge initially), the value of α is ____.

A conducting circular loop is rotated about its diameter at a constant angular speed of 100 rad s⁻¹ in a magnetic field of 0.5 T perpendicular to the axis of rotation.

An insulated cylinder of volume 60 cm³ is filled with a gas at 27°C and 2 atmospheric pressure.

Home / JEE Main Chemistry