oxidation numbers (hw 6k.1 7th ed)

[hannahdaijo_4H]

Why is it that, when identifying oxidized and reduced elements and determining their oxidation numbers, sometimes the oxidation numbers are given for homonuclear diatomic molecules and sometimes its given for just the singular element? Like in 6K.1 (a), the oxidation number for Cr is 6+ (which is what it'd be if Cr = Cr2) and the ox number for C is 2- (rather than 4- if C = C2)? If this makes any sense at all..

[Kelsey Warren 1I]

I think I understand what you're asking (?), and I'm pretty sure that what they give you depends on the compounds involved in the problem and what they're asking you to calculate in the problem. I'm sure that Dr. Lavelle will give us the appropriate oxidation numbers on any test/final problem.

[chaggard]

These different oxidation forms are rare exceptions that I highly doubt we will need to memorize. Just stick with what you know!