balance chemical equation

[mfdeb]

Ca + O2 = CaO

 

Now to balance this equation I have to add another oxygen to the left side but in writing this do I put a 2 infront of O and so inbetween the Ca and the O or .......where does the 2 go?

[Horza2002]

No, if you put the two between the Ca and O (Ca2O THIS IS NOT CORRECT), then that means you have two calcium ions bound to a single oxygen atom. What this reaction makes is in fact two CaO (calcium oxide) molecules.

 

So, you where right you do need to balance the oxygens on the right hand side:

 

Ca + O2 --> 2CaO

 

But this is still not balanced seeing as you now have tywo calcium on the right, so overal:

 

2Ca + O2 --> 2CaO