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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Glitch000 on February 09, 2022, 03:46:10 PM

Title: redox reaction
Post by: Glitch000 on February 09, 2022, 03:46:10 PM
hi, can someone help me with this redox reaction?

CuS + NO-3 + H+  :rarrow: Cu2+ + S + NO + H2O

i used the semi-reaction method and i obteined

3CuS + 8H+ + 2NO-3  :rarrow: 3Cu2+ + 3S +2no + 4H2O

Then i have to write the molecular form and here is my problem

the solution of this exercise is:
3CuS + 8HNO3  :rarrow: 3Cu(NO3)2 + 3S + 2NO +4H2O

I don't understand how we arrive at 3Cu(NO3)2
the solution said to add 6NO3- in the products but i don't understand why...
Title: Re: redox reaction
Post by: Borek on February 09, 2022, 06:20:09 PM
How many Cu(NO3)2 molecules can you make from three Cu2+ ions?

How many NO3- anions have to be added for that?
Title: Re: redox reaction
Post by: Orcio_87 on February 10, 2022, 10:16:16 AM
Quote
3 CuS + 8 H+ + 2 NO3-  :rarrow: 3 Cu2+ + 3 S +2 NO + 4 H2O
I think that your answer is better, because the question was to balance the reaction of CuS with H+ and NO3- not with HNO3.
Title: Re: redox reaction
Post by: Borek on February 10, 2022, 02:55:55 PM
Quote from: Orcio_87 on February 10, 2022, 10:16:16 AM
I think that your answer is better, because the question was to balance the reaction of CuS with H+ and NO3- not with HNO3.

OP clearly stated they are expected to write molecular reaction equation.
Title: Re: redox reaction
Post by: Orcio_87 on February 10, 2022, 03:21:08 PM
Sorry, I missed that.