•• The water molecule is partially ionic, in that an electron is partially transferred fro...

•• The water molecule is partially ionic, in that an electron is partially transferred from each hydrogen to the oxygen, as indicated in Fig. 1, where q denotes the magnitude of each of the two charges transferred. (a) Write down the electric dipole moment p of the H2O molecule in terms of the charge q, the H─O bond length d, and the angle θ. (Note: The dipole moment of two charges q and −q a distance d apart is a vector of magnitude qd pointing from the negative to the positive charge. Thus, H2O has two dipoles p1 and p2 as shown, and the total moment is p = p1 + p2.) (b) The measured values are p = 6.46 × 10−30 C · m, d = 0.0956 nm, and θ = 104.5°. Find the magnitude q of the charge transferred and express it as a fraction of the electron charge e.

FIGURE 1