Use VSEPR theory to decide which one of the following molecules and ions will definitely have at least one 90 $\degree$ bond angle in it. (In each case except water, the central atom is the first one in the formula.)

Question

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Using VSEPR theory, we can predict the shape of a molecule based on the number of electron groups (bonded and lone pairs) around the central atom. A) AlCl₄^¯ - There are 6 electron groups around Al, which gives us a octahedral shape. There are no 90° angles in an octahedron. B) NH₃ - There are 4 electron groups around N, which gives us a tetrahedral shape. All four bond angles will be 109.5°. C) PCl₅ - There are 5 electron groups around P, which gives us a trigonal bipyramidal shape. The bond angles between the equatorial positions are 120°, and the axial position is 180° from the equatorial positions. Therefore, there must be at least one 90° angle between an axial position and an equatorial position. D) CO₂ - There are 3 electron groups around C, which gives us a trigonal planar shape. All three bond angles will be 120°. E) H₂O - There are 4 electron groups around S, which gives us a tetrahedral shape. One of the electron groups is a lone pair, which will create a slight distortion in the bond angles but not enough to create a 90° angle.

Use VSEPR Theory to Decide Which One of the Following °\degree°

Use VSEPR Theory to Decide Which One of the Following $\degree$