A sample of HCl gas is placed in an electric field of 2.5 × 104 N C–1. The dipole moment of each HCl molecule is 3.4 × 10–30 Cm. Find the maximum torque that can act on a molecule.


Given:
Electric field : E = 2.5 × 104 N C–1
Dipole moment of each HCl molecule :
P = 3.4 × 10–30 cm = 3.4 × 10–30 Cm .

Formula used:
Torque acting on a dipole is given as
Where, τ is the torque acting on the dipole, P is the dipole moment of the HCl molecules and E is the electric field.
τ = PEsinθ

For maximum torque θ = 90°
Thus sin(90) = 1


Hence a maximum of 8.5× 10-26 Nm of torque can act on a HCl molecule.


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