Three possible dihedral angles for H 2 O 2 (0, 90, and 180) are shown in Fig.

Question:

Three possible dihedral angles for H₂O₂ (0°, 90°, and 180°) are shown in Fig. 1.6.

(a) Assume that the H₂O₂ molecule exists predominantly in one of these arrangements. Which of the dihedral angles can be ruled out by the fact that H₂O₂ has a large dipole moment (2.13 D)? Explain.

(b) The bond dipole moment of the O—H bond is tabulated as 1.52 D. Use this fact and the overall dipole moment of H₂O₂ in part (a) to decide on the preferred dihedral angles in H₂O₂. Take the H—O—O bond angle to be the known value (96.5°). $[] HC-N :O: HC-N :O: \.. (1.6)$