Week 11 (Comparing Strengths of Reducing/Oxidizing Agents)

Question 1

Extraction

Answer 1

-the process of separating a substance from a mixture or matrix using a solvent
-for heptane and water, the more dense solution settles on the bottom and the less dense on the top
-heptane is non-polar, so when shaken, a non-polar halogen will move from aqueous layer to heptane layer, while the polar cations/anions will stay in aqueous layer
-this allows use to seperate halogens from ionic impurities

Question 2

Comparing strengths of oxidizing and reducing agents

Answer 2

-if a reaction occurs in the forward direction but not in the reverse, then you can observe which reactant is a better reducing agent (loses electrons) and which is a better oxidizing agent (gains electrons
-a change in color of solution indicates if reduction/oxidation has occurred

Question 3

Halogens in redox reactions

Answer 3

-halogens are very reactive (highly electronegative)
-they have great affinity for electrons and act as oxidizing agents
-halogens display oxidation states ranging from -1 to +7

Question 4

Redox vs ion-exchange reaction rates

Answer 4

-redox reactions are slower than ion-exchange reaction rates

Question 5

Permanganate

Answer 5

-MnO₄⁻
-oxidizing agent
-appears purple

Question 6

Manganate

Answer 6

-MnO₄²⁻
-appears green
-result of MnO₄⁻ in very basic medium

Question 7

Manganese dioxide

Answer 7

-MnO₂
-appears brown
-result of MnO₄⁻ in neutral/basic medium
-acts as catalyst for redox of MnO₄⁻
-appears as dark precipitate

Question 8

Manganese ion

Answer 8

-Mn²⁺
-colorless
-result of MnO₄⁻ in acidic medium
-acts as catalyst for redox of MnO₄⁻