urea

[205957986]

i am having trouble calculating the lewis structure of urea, can anyone help?

[Averie Moore 2F]

Urea, CH4N2O, can also be written as CO(NH2)2, which gives a bit more information about the structure. The total number of valence electrons adds up to 24. The carbon goes in the center because it is the least electronegative and the 2 NH2 groups will be on either side. From this, you can see that the carbon has to bond with the nitrogen so you know where all your atoms go at this point. The oxygen must also double bond to the carbon because it needs an octet. Then, you fill in the rest of the single bonds and put your extra valence electrons on the nitrogens as lone pairs to satisfy the octet rule. When you check the formal charge in this structure, it is zero.

[Shaniya Kerns 4D]

I would start with placing the first nitrogen element to the right then connecting it to a carbon with a single bond then connecting the carbon to the last nitrogen with a single bond. like, N--C--N, then placing the hydrogens around the nitrogens evenly, connecting them with a single bond then add the lone pairs to the nitrogens because of nitrogens tendency to have 5 valence electrons. when the outsides are complete, I would recommend connecting the oxygen above carbon with a double bond because it does not violate the octet rule and placing the lone pairs around oxygen because of its tendency to have 6 valence electrons. After that is complete I would recommend counting all valence electrons 2 per bond/lone pair. Make sure it adds up to 24 and it should be complete.

[Isabelle Huerta 2I]

The resulting Lewis structure of urea (CO(NH2)2) should show carbon double-bonded to oxygen and single-bonded to two nitrogen atoms, each nitrogen bonded to two hydrogen atoms.