Oxidation and Reduction Chapter 20

Refer to the structures of the four ions shown, which are dichromate (Cr₂O₇^2-), permanganate (MnO₄^-), thiosulfate (S₂O₃^2-), and triiodide (I₃^-) ions.

Which structure best represents the permanganate ion?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-3

Refer to the structures of the four ions shown, which are dichromate (Cr₂O₇^2-), permanganate (MnO₄^-), thiosulfate (S₂O₃^2-), and triiodide (I₃^-) ions.

Which structure best represents the dichromate ion?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-3

Answer the following questions using the unbalanced half-reaction:

Cr₂O₇^2- + H⁺ --> Cr³⁺ + H₂O

What is the oxidation number of Cr in Cr₂O₇^2-?

• -2

• +3

• +5

• +6

Tags

NGSS.HS-PS1-2

Answer the following questions using the unbalanced half-reaction:

Cr₂O₇^2- + H⁺ --> Cr³⁺ + H₂O

How many H⁺ ions are in the balanced half reaction?

• 5

• 8

• 12

• 14

Answer the following questions using the unbalanced half-reaction:

Cr₂O₇^2- + H⁺ --> Cr³⁺ + H₂O

How many electrons are needed (and on which side of the half-reaction) to balance the electron transfer?

• 4 on the right

• 8 on the right

• 3 on the left

• 6 on the left

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which equation represents an oxidation-reduction reaction?

• 2 HCl(aq) + Na₂CO₃(s) --> 2 NaCl(aq) + CO₂(g) + H₂O(l)

• 2 HCl(aq) + Zn(s) --> H₂(g) + ZnCl₂(aq)

• HCl(aq) + AgNO₃(aq) --> AgCl(s) + HNO₃(aq)

• HCl(aq) + NH₃(g) --> NH₄Cl(s)

Which is the net ionic equation for the nitric acid oxidation of iron(II) chloride to form iron(III) chloride and nitrogen(II) oxide?

• 3 FeCl₂ + 4 HNO₃ --> 2 FeCl₃ + Fe(NO₃)₃ + N + 2 H₂O

• 3 Fe²⁺ + 6 Cl + 4 NO₃^- + 4 H⁺ --> 3 Fe³⁺ + 6Cl + 3NO₃^- + NO + 2 H₂O

• 3 Fe²⁺ + NO₃^- + 4 H⁺--> 3 Fe³⁺ + NO + 2 H₂O

• 3 Fe²⁺ + NO₃^- + 6 H⁺--> 3 Fe³⁺ + N²⁺ + 3 H₂O

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Of the substances listed, in which one can the nitrogen atom not be oxidized further?

• N₂

• NH₃

• N₂O₅

• NaNO₂

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

2 MnO₄^- + 5 H₂O₂ + 6H⁺ --> 2 Mn²⁺ + 5 O₂ + 8 H₂O

What volume of 0.0100 M KMnO₄ solution is needed to react with 10.0 mL of 0.200 M H₂O₂?

• 20.0 mL

• 80.0 mL

• 200. mL

• 500. mL

Sn²⁺ + MnO₄^- + H⁺ --> Sn⁴⁺ + Mn²⁺ + H₂O

What is the Sn²⁺/MnO₄^- ratio when the oxidation-reduction reaction above is correctly balanced?

• 1/2

• 2/3

• 5/2

• 7/2