What coefficient of KCI

Start with the unbalanced equation:

KClO

3

→

KCl

+

O

2

A method that often works is to balance everything other than

H

and

O

first, then balance

O

, and finally balance

H

.

Another rule is to start with what looks like the most complicated formula.

The most complicated formula looks like

KClO

3

.

We put a

1

in front of it and mark the

1

to remind ourselves that the number is now fixed.

We can't change a coefficient unless we run into a roadblock (like having to use fractions).

My teacher never let me use fractions.

My solution when I hit a roadblock was to erase all the numbers and then start over again with a 2 as the starting coefficient.

We start with

1

KClO

3

→

KCl

+

O

2

Balance

K

:

We have 1

K

on the left, so we need 1

K

on the right. We put a

1

in front of the

KCl

.

1

KClO

3

→

1

KCl

+

O

2

Balance

Cl

:

Cl

is already balanced, with 1

Cl

on each side.

Balance

O

:

We have 3

O

atoms on the left and only

2

on the right. We need 1½

O

2

molecules on the right. Uh, oh! Fractions!

We start over with a 2 as the coefficient.

2

KClO

3

→

2

KCl

+

O

2

Now we have 6

O

atoms on the left. To get 6

O

atoms on the right, we put a 3 in front of the

O

2

.

2

KClO

3

→

2

KCl

+

3

O

2

Every formula now has a fixed coefficient.

We should have a balanced equation.

Let's check:

Left hand side: 2

K

, 2

Cl

, 6

O

Right hand side: 2

K

, 2

Cl

, 6

O

All atoms balance.

The balanced equation is