CHEMICAL BONDING (d) Resonance in borate ion is exactly analogous to that in carbonate B 1. 17 There are four B-H bonds in BH4 The four electron pairs surround boron in a tetrahedral orien- tation.TheH—B— H angles are 109.5° 1. 18 (b) Nitrogen in ammonium ion is surrounded by 8 electron bonds are directed toward the corners of a tetrahedron s in four covalent bonds These four H H (c) Double bonds are treated as a single unit when deducing the shape of a molecule using the VSEPR model. thus azide ion is linear The nnn angle is180° (d) Since the double bond in carbonate ion is treated as if it were a single unit, the three sets of electrons are arranged in a trigonal planar arrangement around carbon. The OCO angle is 120. 1. 19 (b) Water is a bent molecule, and so the individual o-H bond dipole moments do not cancel. Water has a dipole moment Individual oh bond Direction of net (c) Methane, CHa, is perfectly tetrahedral, and so the individual(small)C-H bond dipole (d) Methyl chloride has a dipole moment H Directions of bond dipole Direction of molecular dipole moment Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE WebsiteCHEMICAL BONDING 7 (d) Resonance in borate ion is exactly analogous to that in carbonate. and 1.17 There are four B@H bonds in BH4 . The four electron pairs surround boron in a tetrahedral orien￾tation. The H@B@H angles are 109.5°. 1.18 (b) Nitrogen in ammonium ion is surrounded by 8 electrons in four covalent bonds. These four bonds are directed toward the corners of a tetrahedron. (c) Double bonds are treated as a single unit when deducing the shape of a molecule using the VSEPR model. Thus azide ion is linear. (d) Since the double bond in carbonate ion is treated as if it were a single unit, the three sets of electrons are arranged in a trigonal planar arrangement around carbon. 1.19 (b) Water is a bent molecule, and so the individual O@H bond dipole moments do not cancel. Water has a dipole moment. (c) Methane, CH4, is perfectly tetrahedral, and so the individual (small) C@H bond dipole moments cancel. Methane has no dipole moment. (d) Methyl chloride has a dipole moment. C Cl H H C Cl H H Directions of bond dipole moments in CH3Cl Direction of molecular dipole moment H H O H H O H H Individual OH bond moments in water Direction of net dipole moment C O O O The OCO angle is 120º.   N N N   The NNN angle is 180°. Each HNH angle is 109.5º. N H H H H O O O B B O O O      O O O  B  B O O  O    Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website