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# the p block: nitrogen and group 5 question help watch

1. 3) one of the stages in the denitrification process brought about by bacteria in the soil involves the conversion of NO into N2O.

a) what is the change in the oxidation state of nitrogen in this conversion?

i know in the NO the oxidation state is +2 (right?) but what is it in the N2O?

b) write a balanced half equation for the conversion
NO --> N2O
you will need to add electrons, H2O molecules and H+ ions to balance the equation.

ok this i dont even know where to start.

2. (Original post by SeekerOfKnowledge)
3) one of the stages in the denitrification process brought about by bacteria in the soil involves the conversion of NO into N2O.

a) what is the change in the oxidation state of nitrogen in this conversion?

i know in the NO the oxidation state is +2 (right?) but what is it in the N2O?

b) write a balanced half equation for the conversion
NO --> N2O
you will need to add electrons, H2O molecules and H+ ions to balance the equation.

ok this i dont even know where to start.

Anyway, yes you are right, it is +2 for N in NO because O has oxidation state of -2 and overall oxidation state is zero as it is a neutral compound; if you read the site, you'd know this!
ie N + (-2) = 0 => therefore N = +2

If you do the same for N2O: 2N + (-2) = 0, so what is N?

If is half equation, because there will be electrons being added on one side of the eqn. NB, a fully balanced equation won't have any electrons in them.
So, NO ---> N2O
Balance number of nitrogen first. then balance with number of electrons, according to your oxidation state values from previous parts of this question
3. (Original post by shengoc)

Anyway, yes you are right, it is +2 for N in NO because O has oxidation state of -2 and overall oxidation state is zero as it is a neutral compound; if you read the site, you'd know this!
ie N + (-2) = 0 => therefore N = +2

If you do the same for N2O: 2N + (-2) = 0, so what is N?

If is half equation, because there will be electrons being added on one side of the eqn. NB, a fully balanced equation won't have any electrons in them.
So, NO ---> N2O
Balance number of nitrogen first. then balance with number of electrons, according to your oxidation state values from previous parts of this question
ok so the oxidation state is +1

i dont understand how to do the second part

say for example:
2NO -> N2O
i cant balance
4. (Original post by SeekerOfKnowledge)
ok so the oxidation state is +1

i dont understand how to do the second part

say for example:
2NO -> N2O
i cant balance
You forgot you mentioned:
"you will need to add electrons, H2O molecules and H+ ions to balance the equation."

NO + H+ + e- ---> N2O + H2O
5. 2NO + 2H+ + e ---> N2O +H2O
?
6. Yes, except that the charges aren't balanced.
the left side has charge of 1+ due to (2H+ + e- = H+) whereas the right side has neutral charge. So you need to balance this.
7. if you haven't figured it out yet
Spoiler:
Show
you need 2e- on the left side (instead of one electron)

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