Page 1 of 1
Balance Reaction Using Oxidation States Method
Posted: Sat Mar 21, 2020 2:21 pm
by romihan95
I need help balancing this reaction on my chemistry homework, please!
Must be done using oxidation states method
NO3^- + Zn +OH^- + H2O = Zn(OH)4^2- + NH3
Posted: Sat Mar 21, 2020 2:48 pm
by ChenBeier
In alkaline envirement oxidation by adding of OH- on educt side and water on product side, if oxygen is involved ,by reduction vise versa.
Look for redox pairs
Redox pair NO3- / NH3 and Zn/ [Zn( OH)4]2-
NO3- + 6 H2O => NH3 + 9 OH- add water and OH-
Zn + 4 OH- => [Zn(OH)4]2- only add OH- no oxygen transfer.
Balance charges by using electrons
NO3- + 6 H2O + 8 e- => NH3 + 9 OH- Reduction
Zn + 4 OH- => [Zn(OH)4]2- + 2 e- Oxidation
kgV of electron is 8
Multiplication of second equation by 4
4 Zn + 16 OH- => 4 Zn(OH)4]2- + 8 e-
Addition
4 Zn + NO3- + 6 H2O + 7 OH- => 4 [Zn(OH)4]2- + NH3