Question

CO2+H20 gives C6H12O6+O2+H2O

How to balance this equation as per short cut method taught in byju's class session

Answer 1

Start with the Carbon. It's really a toss-up between it and the Hydrogen, but you can just ignore the Oxygen off the top, since it is by itself on one side, making it easy to fix at the end.

Since you have minimum 6 Carbons on the right, you need at least 6 CO2 to balance the Carbon, as CO2 has only 1 each.

6CO2 + H2O -----> C6H12O6 + O2

The Carbon is balanced, so let's try to balance the Hydrogen now. Since there are 12 Hydrogens on the right, we need 6 H2O to balance, as there are 2 Hydrogens in each.

6CO2 + 6H2O -----> C6H12O6 + O2

Checking both sides again, we see that both sides have the same number of Carbon and Hydrogen, so now let's look at the Oxygen. Counting the left side, we see that there are 6(2) + 6 = 18 Oxygen. However, the right side only has 6 + 2 = 8 Oxygen. Fortunately, the difference of 10 is an even number, so all we need to do is increase the coefficient for O2 until we get 18 on the right side. Since each additional O2 provides 2 additional Oxygen, we will need 10/2=5 ADDITIONAL O2. The new coefficient should be 6, giving:

6CO2+6H2O -----> C6H12O6 + 6O2

Checking both sides, we now see that it is balanced