Answer:
2
H
2
+
O
2
=
2
H
2
O
Explanation:
From the original equation, you first need to write each component separately.
H
2
+
O
2
=
H
2
O
Left side: H = 2 ; O = 2 (number based on the subscript)
Right side: H = 2 ; O = 1 (number based on the subscripts; no subscript means that the element is just 1)
Notice that the number of H is already balance but the number of O is not. In order to balance the O, you need to multiply the element by 2, but you CANNOT do this by simply changing the subscript.
Hence,
H
2
+
O
2
=
2
H
2
O
Left side: H = 2 ; O = 2
Right side: H = 2 x 2 = 4 ; O = 1 x 2 = 2
Now, notice that the number of O is now balance (both are 2) but the number of H is not (since
H
2
O
is a substance and not an element, you need to multiply everything by 2). So, what to do?
You also multiply the left side H by 2. Hence,
2
H
2
+
O
2
=
2
H
2
O
Left side: H = 2 x 2 = 4 ; O = 2
Right side: H = 2 x 2 = 4 ; O = 1 x 2 = 2
The equation is now balanced.
