To draw the Lewis structures for NO2+, NO2, and NO3, we need to follow the steps for drawing Lewis structures, which include counting the total number of valence electrons, arranging the atoms, and distributing the electrons to satisfy the octet rule.
NO2+ (Nitronium Ion)
1. Count the valence electrons: Nitrogen has 5 valence electrons, and each oxygen has 6. Since it’s a positive ion, we subtract one electron. Total valence electrons = 5 + 6 + 6 – 1 = 16.
2. Arrange the atoms: Nitrogen is the central atom with two oxygen atoms attached.
3. Distribute the electrons: Nitrogen forms a double bond with each oxygen, using 4 electrons. The remaining 12 electrons are placed as lone pairs on the oxygen atoms.
4. The Lewis structure shows a linear shape with a bond order of 2.
NO2 (Nitrogen Dioxide)
1. Count the valence electrons: Nitrogen has 5 valence electrons, and each oxygen has 6. Total valence electrons = 5 + 6 + 6 = 17.
2. Arrange the atoms: Nitrogen is the central atom with two oxygen atoms attached.
3. Distribute the electrons: Nitrogen forms a double bond with one oxygen and a single bond with the other, using 6 electrons. The remaining 11 electrons are placed as lone pairs on the oxygen atoms and nitrogen.
4. The Lewis structure shows a bent shape with a bond order of 1.5.
NO3- (Nitrate Ion)
1. Count the valence electrons: Nitrogen has 5 valence electrons, and each oxygen has 6. Since it’s a negative ion, we add one electron. Total valence electrons = 5 + 6 + 6 + 6 + 1 = 24.
2. Arrange the atoms: Nitrogen is the central atom with three oxygen atoms attached.
3. Distribute the electrons: Nitrogen forms a double bond with one oxygen and single bonds with the other two, using 8 electrons. The remaining 16 electrons are placed as lone pairs on the oxygen atoms.
4. The Lewis structure shows a trigonal planar shape with a bond order of 1.33.
Order of Increasing Bond Order
Based on the bond orders calculated from the Lewis structures, the order of increasing bond order is:
NO3- (1.33) < NO2 (1.5) < NO2+ (2)