Question

which of the following equations is balanced?

A. 4P+5O2 ------>2P2O5
B. P+O2 -------->P2O5
c. 4P+2O2 ------>2P4O5
D. P+2O2 ------->PO2

Answer 1

@Abstract_Undercover @Englishguy @girlmeetsworld

Answer 2

which equation has \(equal\) numbers of \(each \space type\) of atom on both sides of the arrow?

Answer 3

I'll do one of them as an illustration of what JFraser said:

\[\text{P}+\text{O}_2 \rightarrow\text{P}_2\text{O}_5\]

On the left side we have:
1 P
2 O

On the right side we have
2 P
5 O

That's not balanced, as the numbers are not the same.

A balanced version of that equation would be:
\[4\text{P} + 5\text{O}_2\rightarrow 2\text{P}_2\text{O}_5\]
Here we would have on the left side 4 P atoms and 5*2 = 10 O atoms
On the right side we have 2 molecules each containing 2 P atoms and 5 O atoms, giving a total of 2*2 = 4 P atoms and 2*5 = 10 O atoms, which balances the left side exactly.