CHEM QUESTION (REDOX REACTION)

1
1 Purple KMnO4(aq) & colorless KI(aq) are mixed. Final color is brown.
2 Oxidizing agent is KMnO4/H⁺. Reducing agent is KI.
3 I⁻ ion is oxidized. MnO4⁻ ion is reduced.


2
1 Orange K2Cr2O7(aq) & colorless KI(aq) are mixed. Final color is greenish brown.
2 Oxidizing agent is K2Cr2O7. Reducing agent is KI.
3 I⁻ ion is oxidized. Cr2O7²⁻ ion is reduced.


3
1 Brown Br2(aq) & colorless KI(aq) are mix. The brown color is slightly deeper (or no apparent observable change).
2 Oxidizing agent is Br2. Reducing agent is KI.
3 I⁻ ion is oxidized, and Br2 is reduced.


4
1 Deep purple KMnO4(aq) & pale green FeSO4(aq) are mixed. Final color is yellowish brown.
2 Oxidizing agent is KMnO4/H⁺. Reducing agent is FeSO4.
3 Fe²⁺ ion is oxidized. MnO4⁻ ion is reduced.


5
1 Orange K2Cr2O7(aq) & pale green FeSO4(aq) are mixed. Final color is yellowish green.
2 Oxidizing agent is K2Cr2O7. Reducing agent is FeSO4.
3 Fe²⁺ ion is oxidized. Cr2O7²⁻ ion is reduced.


6
1 Brown Br2(aq) & pale green FeSO4(aq) solution are mixed. Final color is yellowish brown (or yellow).
2 Oxidizing agent is Br2. Reducing agent is FeSO4.
3 Fe²⁺ ion is oxidized. Br2 is reduced.


7
No reaction occurs.
If Na2SO3 is used instead of Na2SO4:
1 Deep purple KMnO4(aq) is decolorized.
2 Oxidizing agent is KMnO4/H⁺. Reducing agent is Na2SO3.
3 SO3²⁻ ion is oxidized. MnO4⁻ ion is reduced.


8
No reaction occurs.
If Na2SO3 is used instead of Na2SO4:
1 Orange K2Cr2O7 solution turns green.
2 Oxidizing agent is K2Cr2O7/H⁺. Reducing agent is Na2SO3.
3 SO3²⁻ ion is oxidized, and Cr2O7²⁻ ion is reduced.


9
No reaction occurs.
If Na2SO3 is used instead of Na2SO4:
1 Brown Br2 solution is decolorized.
2 Oxidizing agent is Br2. Reducing agent is Na2SO3.
3 SO3²⁻ ion is oxidized. Br2 is reduced.