The dipole moment of water is 1.84D and dipole moment of O-H bond is 1.5D. Calculate the H-O-H bond angle in water.

Explanation

Net dipole moment of a molecule, `mu=(m_1^2 + m_2^2 +2m_1m_2cos theta)^(1//2)`.
Substituting the values of `m_1, m_2`, and `mu` in the relation : `1.84 =[(1.5)^2 + (1.5)^2+2xx1.5xx 1.5 cos theta]^(1//2)`
Squaring both sides, `3.3856= 2.25.+2.25 +4.5 cos theta, cos theta=-0.2476 implies theta=cos (-0.2476) = 104.3^@`