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Guide to Balancing a Chemical Eąuation

STĘPI \v':' Write an eąuation usmg the • correct formulas of tli e reactants and products. - ;■

STEP 4

Check finał eąuation for hałance.

Write an eąuation, using the correct formulas. As a first step, we write the eąuation using the correct formulas for the reactants and products.

^C«4(S) + o₂(g)-- C0₂(g) + H₂0(g)

Determine if the equation is balanced. When we compare the atoms on the reactant side with the atoms on the product side, we see that there are morę hydrogen atoms on the left side and morę oxygen atoms on the right.

CH₄(g) + 0₂(g)-»

1C 4 H 20

CO ₂(g) + H₂0 (g)

1    C Balanced

2    H Not balanced

3    O Not balanced

STEP 3

Balance the eąuation one element at a tinie. Balance the hydrogen atoms by placing a coefficient of 2 in front of the formula for water.

CH₄(g) + 0₂(g)-> C0₂(g) + 2H₂0(g)

Then balance the oxygen atoms by placing a coefficient of 2 in front of the formula for oxygen. There are now four oxygen atoms and four hydrogen atoms in both the reactants and products.

CH₄(g) + 20₂(g)-- C0₂(g) + 2H₂0(g)

STEP 4

Check to see if the eąuation is balanced. Rechecking the balanced eąuation shows that the numbers of atoms of carbon, hydrogen, and oxygen are the same for both the reactants and the products. The eąuation is balanced using the lowest possible whole numbers as coefficients.

i *

0    • • *

CH₄(g) + 20₂(g) —► C0₂(g) + 2H₂0(g) Balanced

Reactants    Products

1    C atom    =    1 C atom

4 H atoms    =    4 H    atoms

4 O atoms    =    4 0    atoms

Suppose you had written the eąuation as follows:

2CH₄(g) + 40₂(g)-- 2C0₂(g) + 4H₂0(g) incon-ci

Althougb there are eąual numbers of atoms on both sides of the eąuation, this is not written correctly. Ali the coefficients must be divided by 2 to obtain the lowest possible whole numbers.