Why isn't H2O written as OH2?

Question

Here's a good chemistry question:
Why isn't H2O written as OH2?
Why isn't C6H12O6 written as H12C6O6 or O6C6H12?
Why isn't ... you get the idea.
Why are compounds written as the way they are?
Thanks for all answers!

Answer 1

Generally speaking, we write the posititve cation first and the negative anion second. EX: CuCl2.

If we are writing the formula for a molecular compound (no ions) we write the central atoms first. EX: CH4, CO2

Carbohydrates use the form: C H O due to their name being in that order. Carbo (C) hydr (H) ates (O). EX: C6H12O6, C12H22O11

Answer 2

For inorganic compounds, atoms that tend to form positive ions - hydrogen and the metals - are written first. In organic chemistry, almost all compounds are carbon-based, so it is the first element listed. Complex ions or groups are usually written with oxygen or hydrogen last, as in P03, OH. There have to be such rules so everybody understands what is meant.

Answer 3

For inorganic chemicals you place the "metal," the elemet that gives up the electron, first. So in the case of water Hydrogen gives up electrions to oxygen, so it's written H2O.

For organic compounds, I guess it's just convention. C's first, then H's, then O's, then N's, then F's, Cl's or whatever else is left.

Answer 4

Fe + O2 --> FeO

Mg + O2 --> MgO

H2 + O2 --> H2O

in this case all the atoms that are oxidized (meaning they lose electrons) are written first. that tends to be technique for writing compounds.