[danny411]

acidfied K2cr207 is added to HNO3(aq) what is oxidizing agent

k2cr207 breaks down to cr2072-

HNO3 to NO3-

cr2072----->cr3+

NO3- -----> NO2 or NO

first one has ox number of 6---- 3 so its being reduced...aka its a oxidizing agent

second 5-----> 4 or 2 so its being reduced too ? aka ox agent

either im reading the chart wrong or im misunderstanding how HNO3 reacts in acid ?

[Controlled Substance]

HNO3(aq) is the acid. Can you rephrase your question?

[danny411]

nope...it just asks if you combine those two what is the  oxidizing agent?


but when i worked it out there seems to be two...and that cant be--both reactants can be the same or it wont combine...

not sure how Hno3 breaks down in acid ?

when i use the table or elements its -1 or +1 combined

N can be -3 or +5....

for -3 it must gain 3 electrons==

n +3e-=N3-

N +5 would lose 5

=n---> n5+ + 5e-

haha see i dont know what im doing

[danny411]

Getting it...

HNO3 dissociates...its a strong acid so it 100% ionizes..its also low soluble...

HNO3 + h20 ---> H30 + NO3...

from here use the chart...or half cell method

Hno3----> NO3
                          H+ +e-

so that one is oxidizes and is a RA...

so the one that is a oxidizing agent is cr207

hows that ?

[Astrokel]

Hey danny411,

my bet to this is there will be no reaction taking place since both are pretty strong oxidizing agents, at least not simple reactions.

[danny411]

well i dont know how they break down

does no3 form no or no2 ?

cr207--> c3+

6----3


no3--->no

5---2

those are exactly the same so no reaction would occur thats for sure...

no3--->no2
                     

5--.--3 ?

thats almost the same too ?

[danny411]

k thanks again guys...im working on things...

[Astrokel]

hey danny411,

it really depends on the concentration of the nitric acid HNO3 and even the temperature. I can't be sure whether NO or NO2 will be formed. Maybe someone with knowledge on this could help you, sorry. But im pretty sure there will no reaction that im aware of between potassium dichromate and nitric acid, i could be wrong though 

If HNO3(aq) is an acid like Controlled Substance had said and H2 gas is evolved, then HNO3(aq) is not undergoing a redox reaction but rather an acid-base one, so it won't be an oxidizing agent.

[LQ43]

I would agree with Astrokel, I doubt that any reaction would occur with just these two compounds as they are both strong oxidizers.

Notice the initial oxidation states and that you keep writing reduction half reactions for both, what can you conclude?


Adding another compound that could be oxidized to the mix can tell you if dichromate or nitrate would act as the oxidizer.

Ex. 3 KNO2 + K2Cr2O7 + 8 HNO3 --> 2 Cr(NO3)3 + 5 KNO3 + 4 H2O

This can also be predicted by looking up the reduction potentials of both dichromate and nitrate. Which one is more likely to be reduced, and so the better oxidizer?