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Determine o Nox
Posted: Sat Apr 16, 2022 7:49 am
by lidiane
Como determina o nox de cada elemento deste composto?
[(CH3)2N-NH2]
Re: Determine o Nox
Posted: Sat Apr 16, 2022 12:15 pm
by ChenBeier
Please use english.
How do you determine o nox of each element of this compost?
But its not understandable what is meant. Can you described more in detail.
Re: Determine o Nox
Posted: Sat Apr 16, 2022 1:11 pm
by lidiane
ChenBeier wrote: ↑Sat Apr 16, 2022 12:15 pm
Please use english.
How do you determine o nox of each element of this compost?
But its not understandable what is meant. Can you described more in detail.
Sorry, given this compound: 1,1-dimethylhydrazine, the request is to determine the nox of each element in it. Example: H = +1. My difficulty is knowing for the N and C for this more complex compound
[(CH
3)
2NHH
2]
Re: Determine o Nox
Posted: Sat Apr 16, 2022 1:42 pm
by ChenBeier
You talking about oxidationnumber of the elements.
H is +1 in most compounds , -1 in hydrides like NaH.
C can be from +4 to -4 depending on partner. Elektronegativity number.
N can be -3 to + 5 depending on partner
Bonds between the same element here N is 0.
[(CH3)2N-NH2]
H is + 1
C -2 calculated as 3* (+1)H +(-1)N = +2 , what means -2 then for C.
N -2 calculated as 2* (+1)H and also 2*(+1)C = +2 what means -2 for N.
Re: Determine o Nox
Posted: Sat Apr 16, 2022 3:49 pm
by lidiane
ChenBeier wrote: ↑Sat Apr 16, 2022 1:42 pm
You talking about oxidationnumber of the elements.
H is +1 in most compounds , -1 in hydrides like NaH.
C can be from +4 to -4 depending on partner. Elektronegativity number.
N can be -3 to + 5 depending on partner
Bonds between the same element here N is 0.
[(CH
3)
2N-NH
2]
H is + 1
C -2 calculated as 3* (+1)H +
(-1)N = +2 , what means -2 then for C.
N -2 calculated as 2* (+1)H and also 2*
(+1)C = +2 what means -2 for N.
I didn't understand where these numbers that I highlighted in color came from. Could you detail this procedure?
Re: Determine o Nox
Posted: Sun Apr 17, 2022 1:24 am
by ChenBeier
Start in this way. Let say you have ammonia NH3 then N is calculated 3*(+1) H = 3 what means 3 positiv charges have to compensate with 3 negative charges, so the charge is -3 for N.
Now we look on hydrazin H2NNH2. We have one N-N bond what gives 0. So we have to check the only NH2 . Like above we 2*(+1) = 2 , so the Nitrogen has to be -2 in this case.
For C I will explain with CH4, CH3Cl, CH2Cl2 CHCl3 and CCl4
In CH4 we have the same rule like with N . 4 *(+1) = 4 what means C is - 4.
CH3Cl we have 3*(+1) H + 1*(-1)Cl = +2 what means C has to be -2.
In CH2Cl2 we get 2*(+1)H + 2*(-1) Cl =0, C is 0.
In CHCl3 we get 1*(+1)H + 3*(-1) Cl = -2 , now carbon is +2
And finally CCl4 is 4*(-1) Cl = -4 what means carbon get the maximum of + 4
Now our Molecule [(CH3)2NNH2] has two Methyl groups. As we learned above CH3-Cl C got -2. Instead of the Cl we have a N what must have then also -1 like the chlorine. Each methyl group delivers +1 what gives -2 for nitrogen. So the calculation is
C -2 calculated as 3* (+1)H +(-1)N = +2 , what means -2 then for C.
N -2 calculated as 2* (+1)H and also 2*(+1)C = +2 what means -2 for N
For Methyl-amin we have 3* (+1)H plus one bond to N, what gives (-1)N = +2, carbon therefore -2.
Re: Determine o Nox
Posted: Sun Apr 17, 2022 8:26 am
by lidiane
ChenBeier wrote: ↑Sun Apr 17, 2022 1:24 am
Start in this way. Let say you have ammonia NH
3 then N is calculated 3*(+1) H = 3 what means 3 positiv charges have to compensate with 3 negative charges, so the charge is -3 for N.
Now we look on hydrazin H
2NNH
2. We have one N-N bond what gives 0. So we have to check the only NH
2 . Like above we 2*(+1) = 2 , so the Nitrogen has to be -2 in this case.
For C I will explain with CH
4, CH
3Cl, CH
2Cl
2 CHCl
3 and CCl
4
In CH
4 we have the same rule like with N . 4 *(+1) = 4 what means C is - 4.
CH
3Cl we have 3*(+1) H + 1*(-1)Cl = +2 what means C has to be -2.
In CH
2Cl
2 we get 2*(+1)H + 2*(-1) Cl =0, C is 0.
In CHCl
3 we get 1*(+1)H + 3*(-1) Cl = -2 , now carbon is +2
And finally CCl
4 is 4*(-1) Cl = -4 what means carbon get the maximum of + 4
Now our Molecule [(CH
3)
2NNH
2] has two Methyl groups. As we learned above CH
3-Cl C got -2. Instead of the Cl we have a N what must have then also -1 like the chlorine. Each methyl group delivers +1 what gives -2 for nitrogen. So the calculation is
C -2 calculated as 3* (+1)H +(-1)N = +2 , what means -2 then for C.
N -2 calculated as 2* (+1)H and also 2*(+1)C = +2 what means -2 for N
For Methyl-amin we have 3* (+1)H plus one bond to N, what gives (-1)N = +2, carbon therefore -2.
Thanks for the explanation. I was confused because as nitrogen is from the 5A family and tends to want 3 electrons to complete the octet, the oxidation number would be -3 and not -1, as you did in allusion to Cl, which is from the 7A family and needs only 1 electron to complete octet
Re: Determine o Nox
Posted: Sun Apr 17, 2022 10:07 am
by ChenBeier
I think you dont understand the System. Of course is nitrogen still 3valent. The calculation is based on the bond. The Nitrogen bond to 2 CH3- and one bond to the other nitrogen. On the other side there 2 bonds to H and one to the first nitrogen.
But this has nothing to do with the calculation. A --NH2 is -1 like a -OH is also -1. The nitrogen is -3 and the oxygen is - 2.
Re: Determine o Nox
Posted: Sun Apr 17, 2022 10:31 am
by lidiane
ChenBeier wrote: ↑Sun Apr 17, 2022 10:07 am
I think you dont understand the System. Of course is nitrogen still 3valent. The calculation is based on the bond. The Nitrogen bond to 2 CH
3- and one bond to the other nitrogen. On the other side there 2 bonds to H and one to the first nitrogen.
But this has nothing to do with the calculation. A --NH
2 is -1 like a -OH is also -1. The nitrogen is -3 and the oxygen is - 2.
ok, thank you so much. Now i get it