AP Chemistrymediummcq1 pt
What is the oxidation number of chromium in K₂Cr₂O₇?
A.+6
B.+3
C.+12
D.−2
Explanation
Core Concept
Set up: 2(+1) + 2(Cr) + 7(−2) = 0, so 2(Cr) = +12 and Cr = +6. Oxygen is −2 and potassium +1 by the standard rules.
Correct Answer
A+6
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