Redox Reactions Homework: Cr+2, K2Cr2O7, HNO3 Answers

[Fusilli_Jerry89]

Homework Statement

1) Give the resultant fomula for: Cr2+ gets reduced.

2) Will the following reaction occur? Acidified K2Cr2O7 solution is added to HNO3(nitric acid).

Homework Equations

N/A

The Attempt at a Solution

1) I put: Cr+2 + 2e- ---> Cr(s); I have one question though...doesn't this half-reaction not exist?

2) I put no for this question because I saw that all 4 species are oxidizers. But I am just wondering, if it says acidified K2Cr2O7, does that just refer to: the reaction with Cr2O7-2 that includes 14H+?

 

[chemisttree]

The answer to the first question is correct. For the second question you should consult a table of the electrochemical series. You might find this in an Appendix of your textbook or you can consult the CRC Handbook of Chemistry and Physics.

 

[Borek]

In general chemisttree is right that you should consult tables. However, you mix two substances that are already oxidized. Neither HNO3 nor K2Cr2O7 can be further oxidized as long as we are not talking about some exotic compounds (to be honest - I am not aware of such compounds, but then I know I don't know everything :) ).