(a) The equilibrium separation of the two nuclei in an

Chapter 42, Problem 42.35

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(a) The equilibrium separation of the two nuclei in an NaCl molecule is 0.24 nm. If the molecule is modeled as charges \(+e \text { and }-e\) separated by 0.24 nm, what is the electric dipole moment of the molecule (see Section 21.7)? (b) The measured electric dipole moment of an NaCl molecule is \(3.0\times 10^{-29}\mathrm{\ C}\cdot\mathrm{m}\). If this dipole moment arises from point charges \(+q \text { and }-q\) separated by 0.24 nm, what is q? (c) A definition of the fractional ionic character of the bond is q/e. If the sodium atom has charge \(+e\) and the chlorine atom has charge \(-e\), the fractional ionic character would be equal to 1. What is the actual fractional ionic character for the bond in NaCl? (d) The equilibrium distance between nuclei in the hydrogen iodide (HI) molecule is 0.16 nm, and the measured electric dipole moment of the molecule is \(1.5\times 10^{-30}\mathrm{\ C}\cdot\mathrm{m}\). What is the fractional ionic character for the bond in HI? How does your answer compare to that for NaCl calculated in part (c)? Discuss reasons for the difference in these results.