Balance this equations pH3+O2=P4O10+H2O

Because there are 4 P on the right side, we have to put a coefficient of 4 on the left to balance out the P.

This would give us 12 H on the left and 2 H on the right, so we have to put a 6 on the right to balance out the H.

Now we have 16 O on the left and 2 on the right, so a coefficient of 8 is required to balance out the O.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.