Final answer:
For the [OCN]− ion, the correct statements are not present among the given options: the ion has three σ bonds, two π bonds, and is linear with a bond angle of 180°.
Step-by-step explanation:
The question concerning the [OCN]− ion asks which statements are true. Let's evaluate the given options:
- a. There are two σ bonds and two π bonds: This is incorrect. The [OCN]− ion has three σ bonds, one between each pair of atoms (O=C, C−N), and two π bonds, due to the double bonds between C=O and C=N.
- b. The O-C-N angle is 120°: This is incorrect. The [OCN]− ion is linear, which means the O-C-N angle is 180°.
- c. The structure of this ion is best represented as a hybrid of three equivalent resonance structures: This is incorrect. The resonance structures are not equivalent because the atoms have different electronegativities and the negative charge can only be delocalized over the C and N atoms, not on the oxygen atom.
- d. The C atom has an oxidation state of +4: This is incorrect. The oxidation state of C in this case is +2 since oxygen is more electronegative and would typically take on a -2 oxidation state, and nitrogen in this case would also have a -2 oxidation state to balance out the overall -1 charge of the ion.