Question

Chemistry?! Help me balance this redox equation?

Answer 1

I'll balance it for you :D 

HNO3 + P → H3PO4 + NO 

break it down first (to see how many of each atom on each side) so 

H- 1       H-3
N-1        N-1
O-3       O-12
P-1        P-3

now u gotta make the numbers equal on both sides 

make the first H 3 so it's balanced with the other one by putting a 3 in front of it in the equation like this: 

3HNO3 + P → H3PO4 + NO 

that changes the WHOLE equation except the P because it's not attached (so now the N is also 3 and the O as well) 
   
H- 3     H-3
N-3        N-1
O-9       O-12
P-1        P-3

so now the N is imbalanced on the product side, so do the same thing to fix it 

3HNO3 + P → H3PO4 + 3NO 

the O next to the N is now also 3 sooo 

H- 3     H-3
N-3        N-3
O-9       O-15
P-1        P-3

3HNO3 + 3P → H3PO4 + 3NO 

H- 3     H-3
N-3        N-3
O-9       O-15
P-3        P-3

3HNO3 + 3P → H3PO4 + 3NO 

i realized halfway through this that the O is still unbalanced SOMEHOW