Final answer:
In oxalic acid, the Lewis structure has two resonance forms with double bonds between different carbon-oxygen pairs. The oxalate ion also has two resonance forms with double bonds between different carbon-oxygen pairs.
Step-by-step explanation:
In order to draw the Lewis electron dot structures for oxalic acid and the oxalate ion, we need to know the Lewis structures of individual atoms.
Oxygen (O) has 6 valence electrons and Carbon (C) has 4 valence electrons. In oxalic acid (H2C2O4), there are 2 carbon atoms, 4 oxygen atoms, and 2 hydrogen atoms.
The Lewis structure of the oxalate ion (C2O4) is the same as that for oxalic acid, but without the hydrogen atoms.
Resonance forms occur when a molecule or ion can be represented by two or more Lewis structures that have the same arrangement of atoms but different arrangement of electrons. In the case of oxalic acid and the oxalate ion, there are important resonance forms. For oxalic acid, one of the resonance structures has a double bond between one carbon and one oxygen, while the other resonance structure has a double bond between the other carbon and one oxygen. For the oxalate ion, one of the resonance structures has a double bond between one carbon and one oxygen, while the other resonance structure has a double bond between the other carbon and one oxygen.