( Use ↑ and ↓ please ! )
Balancing a chemical equation
$Na$ +
$O_2$
→
$Na_2O $
$4 Na$ $+$ $O_2$ $\longrightarrow$ $2Na_2O$
$CO$ +
$O_2$
→
$CO_2$
$2CO$ $+$ $O_2$ $\longrightarrow$ $2CO_2$
$P_4$ +
$Cl_2$
→
$PCl_5$
$P_4$ $+$ $10Cl_2$ $\longrightarrow$ $4PCl_5$
$SO_2$ +
$O_2$
→
$SO_3$
$2SO_2$ $+$ $O_2$ $\longrightarrow$ $2SO_3$
