Balance the equation: C_3H_8 + O_2 --> CO_2 + H_2O?

Question

I requesting some help to help me *understand* how to do this. Thanks.

Answer 1

C3H8 + 5O2 ===> 3CO2 + 4H2O

First take the number of C's on the left and put that number of C's in CO2 on the right. Next take the number of H's on the left, divide by two, and put that number of H2O's on the right. Count up the number of O's on the right and balance that with the O2's needed on the left. If you come up with an odd number of O's on the left, multiply the whole thing by two.

Answer 2

Any easy way to do this is to first look at your equation and leave compounds together don't try breaking them apart it will only confuse you further (e.g. leave C3H8 together)

At first glance you should see the following number of each element on each side of the equation

Reactant: Product:
C=3 C=1
H=8 O=3
O=2 H=2

__C(3)H(8)+__O(2)-->__CO(2)+__H(2)O

use the underscores ___ as 'blanks' in which to place the coefficients needed to balance the equation

Looking at the equation you should see that there are (3) Carbon atoms on the reactant side and only (1) on the product side so place a (3) in front of CO(2).

1C(3)H(8)+__O(2)--> 3CO(2)+__H(2)O

This will give you C3H6. Your Carbons are now balanced...now let's look at Oxygen and Hydrogen

You should see their are (2) oxygen on the reactant side and (7) on the product side, as well ase (8) Hyrdrogen on the reactant and (2) on the product

Because Hydrogen appears only in H20 on the product side you'll need to balance the Hydrogen first..so by placing a (4) in front of that you will in turn get H8O4

1C(3)H(8)+__O(2)-->3CO(2)+4H(2)O

Now you see you have only (2) Oxygen on the reactant side and (10) total on the product side, and yes you guessed it, by placing a 5 on the reactant side you balance your equation

1C(3)H(8)+5O(2)-->3CO(2)+4H(2)O

Here is an easy way to check:

write down the total number of each element on both sides of the equation like below to make sure you have the same number in each.

Reactant: Product:
C=3 C=3
H=8 H=8
O=10 O=10

and you're done. . it may look daunting but it is rather simple. .

Answer 3

There's got to be the same numbers on each side, so

c3h8+5o2=3co2+4h2o

c3=3c
h8=4h2
5o2=3o2+4o

I hope that helps.