given the formula of a compound or ion, is there any method or formula to know the number of sigma and pi bonds present and the structure of the molecule/ion?
2006-10-06 01:36:10 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Sorry. There is no easy solution here.
Especially in organic chemistry, the structures of many compounds must be committed to memory. Some people can do this easily, but some cannot.
If you can get at least the order of the atoms in the molecule, you can usually figure out the bonding. There will always be a sigma bond between any two adjacent atoms. Then by knowing the usual number of bonds, one can figure out where the pi bonds are.
In some cases, like the compound benzene (C6H6) the six carbon atoms are sigma bound to each other in a ring. Each has a hydrogen atom sigma bound to it. The pi bonds are every other C-C around the ring, but they resonate.
Ions like sulfate (SO4)-2 can also be difficult. Each of the four oxygen atoms has a sigma bond to the sulfur. Two of them also have pi bonds, the two that do not have negative charges.
2006-10-06 01:45:13 · answer #1 · answered by Richard 7 · 66⤊ 0⤋
sorry to dissapoint you, but there is no way to find the number of sigma and pi electrons in a molecule or ion.but here is the method.first figure out the structure of the molecule with a stable configuration.this means that you'll have to find the structure with atoms having 8 electrons either bonded or unbonded in the case of molecules.in the case of ions this must be decided by the number and charge of the ion.
when you know the structure you can automatically find out the number of sigma and pi electrons.this applies especially to organic molecules.knowing the structure also helps in making out the mechanism of certain reactions the molecule takes part in
2006-10-06 03:49:50 · answer #2 · answered by nandini s 1 · 0⤊ 0⤋