Balanced Redox Reactions

     In the reaction Zn + H₂O --> ZnO₂ + H₂
 which element, if any, is oxidized? 

• Zinc
• Hydrogen
• Oxygen
• None

What substance is oxidized in the following reaction?
4Fe + 3O₂ --> 2Fe₂O₃

• Iron
• Fluorine
• Oxygen

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

If in a reaction, copper is reduced; its number of electrons has:

• Increased
• Decreased
• Remained Constant
• Varies Randomly

Tags

NGSS.HS-PS1-2

If an atom loses electrons during a chemical reaction, the atom was:

• Oxidized
• Reduced
• Neutralized
• Precipitated

Tags

NGSS.HS-PS1-2

What element is being Reduced?

• N

• H

• O

• S

Tags

NGSS.HS-PS1-2

What is oxidation number of Cr in Cr₂O_7^2-?

• -2
• +2
• +6
• +12

What is oxidation number of O in O₂ ?

• 0
• -2
• +1
• +2

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Balance the following ACIDIC reactions using changing oxidation number method.

MnO₄⁻(aq) + H⁺(aq) + I⁻ (aq) → Mn²⁺(aq) + I₂(s)

Water is a product of this reaction. What is the coefficient of water in the final balanced equation?

• 8

• 5

• 2

• 16

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Balance the following reactions using changing oxidation number method.

MnO₄⁻(aq) + H⁺(aq) + I⁻ (aq) → Mn²⁺(aq) + I₂(s)

How many electrons water compound produced in the reaction?

• 10

• 9

• 8

• 7

WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:

Consider the following REDOX reaction:

Cl₂(g) → ClO⁻(aq) + Cl⁻(aq) (basic solution)

How many OH^- molecules did you add to the reactant side of this reaction when balancing?

• 1

• 2

• 3

• 4