In the final chemical equation, NaCl and O2 are the products that are formed through the reaction between Na2O and Cl2. Before you can add these intermediate chemical equations, you need to alter them by

Answer : The correct option is, (B) multiplying the equation first by 2.
Explanation :
The balanced final chemical reaction will be,
[tex]2Na_2O(s)+2Cl_2(g)\rightarrow 4NaCl(s)+O_2(g)[/tex]
The two intermediate chemical reaction are give :
(1) [tex]2Na(s)+Cl_2(g)\rightarrow 2NaCl(s)[/tex]
(2) [tex]2Na_2O(s)\rightarrow 4Na(s)+O_2(g)[/tex]
First multiplying the equation (1) by 2, we get
[tex]4Na(s)+2Cl_2(g)\rightarrow 4NaCl(s)[/tex]
Now adding both the equations, we get
[tex]2Na_2O(s)+4Na(s)+2Cl_2(g)\rightarrow 4Na(s)+O_2(g)+4NaCl(s)[/tex]
The final chemical reaction are :
[tex]2Na_2O(s)+2Cl_2(g)\rightarrow 4NaCl(s)+O_2(g)[/tex]
Hence, the correct option is, (B) multiplying the equation first by 2.