In: Chemistry
What would be the coefficient in front of H2O if you balanced the following redox reaction in basic solution?
NO2-(aq) + Al(s) → NH3(g) + AlO2-(aq)
The charge on nitrogen in NO2(-) is +3 and on nitrogen in NH3 is -3,so it is undergoing reduction
the charge of Al is 0 and in AlO2(-) is +3 so it is undergoing oxidation
Now it is divided into two half oxidation half and reduction half
Now since all other atoms are balanced now oxygen and hydrogen has to be balanced
oxygen atom is balanced by adding water molecules to side deficient in oxygen side
Now hydrogen atom is balanced by adding H+ ions
Since reaction is in basic medium OH- equal to number of H + ions is added on both side and then H+ and OH- on same side combine to form H2O molecule.
now charges are balanced by adding electrons to side deficient in negative charge
Now electron gain is made equal to electron loss by multiplying oxidation reaction by 2
now adding both the equation
Now simplifying
by putting the states and putting coefficient
coefficient in front of H2O is 1