Answer: Option (C) is the correct option.
Explanation:
When two intermediate chemical equations are combined, the same substance that appears in the same phase can be canceled out, provided that it is a reactant in one intermediate reaction and a product in the other reaction.
For example,
[tex]2Al(s) + 2KOH(aq) + 6H_{2}O\rightarrow 2KAl(OH)_{4}(aq)+ 3H_{2}(g)[/tex] ....(1)
[tex]2KAl(OH)_{4}(aq) + 4H_{2}SO_{4}(aq) + 6H_{2}O(l)\rightarrow 2KAl(SO_{4})_{2}(aq)+ 12H_{2}O(s)[/tex] .........(2)
Cancelling the common species in both the equations as follows.
[tex]2Al(s) + 2KOH(aq) + 6H_{2}O\rightarrow \not{2KAl(OH)_{4}(aq)}+ 3H_{2}(g)[/tex]
[tex]\not{2KAl(OH)_{4}(aq)}+ 4H_{2}SO_{4}(aq) + 6H_{2}O(l)\rightarrow 2KAl(SO_{4})_{2}(aq)+ 12H_{2}O(s)[/tex]
Therefore, on addition we get the equation as follows.
[tex]2Al(s)+ 2KOH(aq) + 4H_{2}SO_{4}(aq) + 22H_{2}O(l)\rightarrow 3H_{2}(g)+ 2KAl(SO_{4})_{2} + 12H_{2}O(s)[/tex]
