Charge & Valency of Chemistry Formulas: Explained

  • Context:
  • Thread starter Thread starter markosheehan
  • Start date Start date
  • Tags Tags
    Chemistry
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
5 replies · 4K views
markosheehan
Messages
133
Reaction score
0
i am confused with charge and valency of some formula.

for carbon dioxide CO oxygen has a charge of -2 and carbon has a charge of +2. I thought though carbon is in 4 so its charge should be +/- 4.for nitrogen monoxide NO oxygen has a charge of 2- usually and nitrogen usually has a charge of -3 so this makes no sense to me as the charge is supposed to balance of the compound and both atoms want to gain electrons which also does not make sense to me.

i have the same problems with dinitrogen tetroxide, nitrogen dioxide,sulfur dioxide, sulphur trioxide, and phosphorous(v) chloride. how are you supposed to know the formula and for these if they all have random charges and do not follow the rules? do you just learn them off?
 
Mathematics news on Phys.org
markosheehan said:
i am confused with charge and valency of some formula.

for carbon dioxide CO oxygen has a charge of -2 and carbon has a charge of +2. I thought though carbon is in 4 so its charge should be +/- 4.for nitrogen monoxide NO oxygen has a charge of 2- usually and nitrogen usually has a charge of -3 so this makes no sense to me as the charge is supposed to balance of the compound and both atoms want to gain electrons which also does not make sense to me.

i have the same problems with dinitrogen tetroxide, nitrogen dioxide,sulfur dioxide, sulphur trioxide, and phosphorous(v) chloride. how are you supposed to know the formula and for these if they all have random charges and do not follow the rules? do you just learn them off?

Yes. Basically you just learn them off, or look them up.

There are some patterns though.
Oxygen always has -2 in practice.
But many other elements have multiple valences in which they have a stable bond.
For instance C is known to have +2 and +4 as stable valences.
Consequently both CO and CO2 are stable.
 
ok thanks. could you explain the bonding in NO. both of these elements want to gain different numbers of electrons so how do they bond to each other.
 
Nitrogen is in group 5, meaning it has 5 electrons in its outermost shell. Oxigen is in group 6 and 'stronger'. So oxigen completes the octet in its outer shell.
A bar or 2 dots close together represent a pair of 2 electrons that is somewhat stable.
A loose dot indicates a single electron, which is highly reactive - it wants to make a pair.
Molecules with a loose electron are called radicals, and they won't exist long given the opportunity to bind another molecule.