Please show step-by-step. I am so lost. Thank you in advance!! :) 1. Write a bal
ID: 834655 • Letter: P
Question
Please show step-by-step. I am so lost. Thank you in advance!! :)
1. Write a balanced equation for the oxidation of phosphorus by nitric acid, which is described by P4 (s) + H+ (aq) + NO3 - (aq) --> H2PO4- (aq) + NO (g)
2. Cyanate ion in waste solutions from gold-mining operations can be destroyed by treatment with hypochlorite ion in basic solution. Write a balanced oxidation-reduction equation for this reaction: OCN- (aq) + OCl- (aq) + OH- (aq) ---> CO3 -2 (aq) + N2(g) + Cl- (aq) + H2O (l). * Hint: Notice that the oxidation half reaction OCN- yields two products)
Explanation / Answer
P4(s) + 8 H+(aq) + 8 NO3(aq) --> 4 H2PO4 (aq) + 8 NO (g)
OCN- (aq) + OCl- (aq) + OH- (aq) --> CO32- (aq) + N2 (g) + Cl- (aq) + H2O(l)
Two half reactions:
OCN-(aq) ---> CO32- (aq) + N2 (g)
OCl- (aq)---> Cl- (aq)
Balance them as if in acid solution:
4 H2O + 2 OCN- ---> 2 CO32- + N2 + 8 H+ + 6 e-
2 e- + 2 H+ + OCl- (aq)---> Cl- (aq) + H2O(l)
Change over to basic:
8 OH- + 2 OCN- (aq)---> 2 CO32- (aq) + N2 (g) + 4 H2O (l) + 6 e-
2 e- + H2O + OCl-(aq) ---> Cl- + 2 OH-
Multiply second half-reaction by 3, add them and delete duplicates.
2OH- + 3 OCl- (aq) + 2 OCN-(aq) -->3 Cl- (aq) + 2 CO32- (aq) + N2 (g) + H2O