Question

Write a balanced chemical equation for process of photosynthesis.

Answer 1

Photosynthesis reaction: CO₂ + H₂O → C₆H₁₂O₆ + O₂ + H₂O 

Balanced equation: 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O 

Step 1: Write the unbalanced equation 

CO₂ + H₂O → C₆H₁₂O₆ + O₂ + H₂O 

Step 2: Compare the number of atoms of reactants with the number of atoms of products. 

	Reactants (left side)	Products (right side)
Element	Number of atoms	Number of stoms
C	1	6
H	2	14
O	3	9

Step 3: Now, first we consider the element having unequal no. of atoms on both sides. Thus, first let us consider carbon atom. If we multiply 6 in the reactant (in CO₂), we will get the equal number of atoms as in product (in C₆H₁₂O₆)

No. of atoms of carbon	Reactant (in CO2)	Product (in C6H12O6)
Initiallly	1	6
To balance	1 x 6 = 6	6

Step 4: Write the resulting equation:

6CO₂ + H₂O → C₆H₁₂O₆ + O₂ + H₂O 

Step 5: Now check whether the equation is balanced or not by comparing the atoms

	Reactants (left side)	Products (right side)
Element	Number of atoms	Number of stoms
C	6	6
H	2	14
O	3	9

We find that the equation is not balanced yet. As the number of 

Hydrogen and oxygen atoms are unequal on the two sides. 

First balance the hydrogen atom. 

Step 6: If we multiply 12 in the reactant (in H₂O) and 6 in the product (in H₂O), we will get the equal number of hydrogen atoms both sides.

No. of atoms of hydrogen	Reactant (in H2O)	Product (in C6H12O6 + H2O)
Initiallly	2	14
To balance	2 x 12 = 24	12 + 2 x 6 = 24

Step 7: Write the resulting equation: 

6CO₂ + 12H₂O → C₆H₁₂O₆ + O₂ + 6H₂O 

Step 8: Now check whether the equation is balanced or not by comparing the atoms.

	Reactants (left side)	Product (right side)
Element	Number of atoms	Number of atoms
C	6	6
H	24	24
O	24	14

We find that the equation is not balanced yet. As the number of oxygen atoms are unequal on the two sides. 

Step 9: Now, we consider oxygen atoms. If we multiply 6 in the product (in O₂), we will get the equal number of atoms as in reactants (in 6CO₂ and 12H₂O)

No. of atoms of oxygen	Reactant (in 6CO2 and 12H2O)	Product (in C6H12O6 + O2 + 6H2O)
Initiallly	24	24
To balance	24	6 + 2 x 6 + 6 = 24

Step 10: Write the resulting equation: 

6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O 

We find that the equation is balanced now. 

Step 11: Write down the final balanced equation:

6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O