Balancing equations (1 Viewer)

[Pepperpie]

How do you balance the equation;
Octane (C8H18) + Air O2 => Carbon dioxide CO2 + Water H2O
Sulfer dioxide + O2 => Sulfer trioxide
Phosphorus + chlorine => Phosphorus pentachloride

Thanks in advanced

 

[kev-kun]

ForOkay hmm...

1) Octane + Air -> CO2 + H20
The rule for balancing a fuel + oxygen -> carbon dioxide +water equations is you balance carbon left to right, hydrogen left to right and then oxygen last from right to left
so therefore;
C8H18 + O2 -> CO2 + H2O
C8H18 + O2 -> 8CO2 + 9H2O
C8H18 + 12.5O2 -> 8CO2 + 9H2O (since there are 25 O in Right side you half it as there are two O molecules)

2) SO2 + O2 -> SO3
There is 1 S and 4 O in LHS and 1 S and 3 O in RHS so it becomes
2SO2 + O2 -> 2SO3 (so that there are equal amounts)

3) P + Cl -> PCl5
This one not too hard;
P + 5Cl -> PCl5 (Just balancing the chlorine's)

Hope that helps!

Edit:
Should add that when balancing equations you are trying to follow the Law of Conservation of Atoms. That being that both the LHS and RHS have the same amount of atoms in the simplest whole number ratio. (Though not always especially for fuel + O2). Anyone correct me if I'm wrong ==''

 

[Pepperpie]

ForOkay hmm...

1) Octane + Air -> CO2 + H20
The rule for balancing a fuel + oxygen -> carbon dioxide +water equations is you balance carbon left to right, hydrogen left to right and then oxygen last from right to left
so therefore;
C8H18 + O2 -> CO2 + H2O
C8H18 + O2 -> 8CO2 + 9H2O
C8H18 + 12.5O2 -> 8CO2 + 9H2O (since there are 25 O in Right side you half it as there are two O molecules)

2) SO2 + O2 -> SO3
There is 1 S and 4 O in LHS and 1 S and 3 O in RHS so it becomes
2SO2 + O2 -> 2SO3 (so that there are equal amounts)

3) P + Cl -> PCl5
This one not too hard;
P + 5Cl -> PCl5 (Just balancing the chlorine's)

Hope that helps!

Edit:
Should add that when balancing equations you are trying to follow the Law of Conservation of Atoms. That being that both the LHS and RHS have the same amount of atoms in the simplest whole number ratio. (Though not always especially for fuel + O2). Anyone correct me if I'm wrong ==''

Thanks so much!!