Question

Why do we have to add h+ in balancing of redox reactions?

Answer 1

Explanation:

H2 is the balanceing character

Answer 2

Answer:

we add it to balance the reaction

Explanation:

okay so basically when balancing redox reactions we have to look for certain points:

adding 2O in the presence of O2 and to balance the number of hydrogen we add H+

so here is an example:

NO3-  + Cr³+  ---> NH3 + Cr2O7²-

okay so lets take the redoz couple NO3-/NH3

NO3- ---> NH3

now we add H2o to the rpoduct side to balance out the number of oxygen molecules

NO3- ---> NH3 + 3H2O

now the number of oxygen molecules is balanced whereas number of hydrogen molecules is not

so now we have to add H+ on the reactant side to balace out the hald reaction

we add 9H+ because we have 3 hydrogen atoms in NH3 and 6 in 3H2O so the number of hydrogen added must be 9

NO3- + 9H+ ---> NH3 + 3H2O

for now the half reaction is balanced in the number if atoms and not the charge so:

in the reactant side we have 1- and 9+ we add them and the answer is 8+

while on the product side the charge is 0 so we have to add 8e- on the reactant side to have an equal charge on both sides

so the final half reaction is :

NO3- + 9H+ + 8e- ---> NH3 + 3H2O

and finally you do the same thing for the other half reaction