306
Electrochemistry II Balancing Equations
produced, as shown by a blue color that appears when a little starch
solution is added Give the equation for the formation of the iodine
(d) When copper is heated in concentrated sulfunc acid, an odor of sulfur
dioxide is noted
(e) A classical operation in quantitative analysis is the use of a Jones reductor, a column of granulated zinc A solution of ferric salts is passed
through this column prior to titration with potassium permanganate Give
the equation for the reaction in the column
(f) Pure hydnodic acid cannot be prepared by adding concentrated sulfunc
acid to sodium iodide and distilling off the hydnodic acid, because of side
reactions One side reaction yields hydrogen sulfide, as noted by the odor
Give the equation for this side reaction
(g) A solution of sodium hypochlonte is heated One of the products is
sodium chlorate
8 Balance the equations given in Problem 3, p 423
PROBLEMS B
9 Find the oxidation number of each atom in the following molecules and ions
(a) S0 3
(c) Zn(I0 3 ) 2
(e) (NH 4 ) 3 PO 4
(g) V 2 Ot
(i) S 2 O 3
2 -
(b) H 2 SO 3
(d) Na 2 O 2
(f) NaH
(h) SiO 3
2 -
0) BiO
+
10 Write balanced ionic half-reactions for the oxidation of each of the following
reducing agents in acid solution
(a) Sn
(c) H 2 C 2 O 4
(e) Br
(b) Sn
2+
(d) H 2 S
(f) Ba
11 Write balanced ionic half-reaction equations for the reduction of each of the
following oxidizing agents in aqueous acid solution
(a) MnO 2 (solid)
(c) C1O 2 ~
(e) H 2 O 2
(g) Fe
2+
(b) Cr 2 0
2 -
(d) I0 3 -
(f) Br 2
(h) Cd
2+
12 Write balanced ionic equations for the following reactions
(a) Fe + Ag
+ -^
(i) H 2 O 2 + ClOj ->
(b) Cd + H
+ -»
0) H 3 AsO 3 + Ce
4+ -+
(c) Cd + H
+ + NO 3 - (dilute) -+
(k) Sn
2+ + C1O 2 - + H
+ ->
(d) C1 2 + HN0 2 -H>
(1) Sn
2+ + Mg —
(e) MnO 4 ~ + H 2 S + H
+ -»
(m) PbO 2 + HNO 2 + H
+ ->
(f) C1O 3 - + Sn
2+ + H
+ -»
(n) Cr 2 O
2 - + H 2 C 2 O 4 + H
+ ->
(g) Br 2 + Fe
2+ ->
(o) C1 2 + T ->
(h) H 2 O 2 + H 2 SO 3 ->
13 Write balanced molecular equations for the reactions in Problem 12 Use
potassium salts of the negative ions and sulfate salts of the positive ions for
the reactants given
14 Complete and balance the following ionic equations for reactions that occur in
aqueous solution The nature of the solution (acidic or basic) is indicated for
each reaction
Electrochemistry II Balancing Equations
produced, as shown by a blue color that appears when a little starch
solution is added Give the equation for the formation of the iodine
(d) When copper is heated in concentrated sulfunc acid, an odor of sulfur
dioxide is noted
(e) A classical operation in quantitative analysis is the use of a Jones reductor, a column of granulated zinc A solution of ferric salts is passed
through this column prior to titration with potassium permanganate Give
the equation for the reaction in the column
(f) Pure hydnodic acid cannot be prepared by adding concentrated sulfunc
acid to sodium iodide and distilling off the hydnodic acid, because of side
reactions One side reaction yields hydrogen sulfide, as noted by the odor
Give the equation for this side reaction
(g) A solution of sodium hypochlonte is heated One of the products is
sodium chlorate
8 Balance the equations given in Problem 3, p 423
PROBLEMS B
9 Find the oxidation number of each atom in the following molecules and ions
(a) S0 3
(c) Zn(I0 3 ) 2
(e) (NH 4 ) 3 PO 4
(g) V 2 Ot
(i) S 2 O 3
2 -
(b) H 2 SO 3
(d) Na 2 O 2
(f) NaH
(h) SiO 3
2 -
0) BiO
+
10 Write balanced ionic half-reactions for the oxidation of each of the following
reducing agents in acid solution
(a) Sn
(c) H 2 C 2 O 4
(e) Br
(b) Sn
2+
(d) H 2 S
(f) Ba
11 Write balanced ionic half-reaction equations for the reduction of each of the
following oxidizing agents in aqueous acid solution
(a) MnO 2 (solid)
(c) C1O 2 ~
(e) H 2 O 2
(g) Fe
2+
(b) Cr 2 0
2 -
(d) I0 3 -
(f) Br 2
(h) Cd
2+
12 Write balanced ionic equations for the following reactions
(a) Fe + Ag
+ -^
(i) H 2 O 2 + ClOj ->
(b) Cd + H
+ -»
0) H 3 AsO 3 + Ce
4+ -+
(c) Cd + H
+ + NO 3 - (dilute) -+
(k) Sn
2+ + C1O 2 - + H
+ ->
(d) C1 2 + HN0 2 -H>
(1) Sn
2+ + Mg —
(e) MnO 4 ~ + H 2 S + H
+ -»
(m) PbO 2 + HNO 2 + H
+ ->
(f) C1O 3 - + Sn
2+ + H
+ -»
(n) Cr 2 O
2 - + H 2 C 2 O 4 + H
+ ->
(g) Br 2 + Fe
2+ ->
(o) C1 2 + T ->
(h) H 2 O 2 + H 2 SO 3 ->
13 Write balanced molecular equations for the reactions in Problem 12 Use
potassium salts of the negative ions and sulfate salts of the positive ions for
the reactants given
14 Complete and balance the following ionic equations for reactions that occur in
aqueous solution The nature of the solution (acidic or basic) is indicated for
each reaction