Answer:
A. balanced
Explanation:
Hello,
In this case, redox reactions undergo when one the elements at the reactants suffers an increase in its oxidation state and other elements suffers a decrease in its oxidation state. Thus, one could consider the following example:
[tex]H_2+I_2\rightarrow HI[/tex]
In that case, both hydrogen and iodine have zero as their oxidation states at the reactants whereas they go +1 and -1 respectively at the hydroiodic acid as shown below:
[tex]H_2^0+I_2^0\rightarrow H^+I^-[/tex]
In such a way, each hydrogen increases by 1 electron (two electrons in total as there two hydrogens) and iodine decreases by 1 electron (two electrons in total as there two iodines). Thus, the balance turns out:
[tex]H_2^0\rightarrow 2H^++2e^-\\I_2^0+2e^-\rightarrow 2I^-\\\\\\2H_2+2I_2\rightarrow 4HI\\\\H_2+I_2\rightarrow 2HI[/tex]
Therefore, redox equations are A. balanced when the total increase in oxidation numbers equals the total decrease in oxidation.
Best regards.
