Redox Review

Redox Review

Multiple Choice

Which statement is true:
Mg → Mg²⁺ + 2e^–

• Mg gains 2 electrons
• Mg_²⁺ loses 2 electrons
• Mg loses 1 electron
• Mg loses 2 electrons

Multiple Choice

The sum of the oxidation numbers in Na₂CO₃ is equivalent to

• 0

• -2

• +1

• -1

Multiple Choice

The sum of the oxidation numbers in SCN^- is equivalent to

• 0

• -1

• +1

• +3

Multiple Choice

Reduction is the ___________ of electrons.

• loss

• gain

• sharing

• transfer

Multiple Choice

Oxidation is the _________ of electrons.

• loss

• gain

• sharing

• transfer

Multiple Choice

Determine the oxidation number of chromium in CrO₄^2-.

• +6

• 0

• +2

• +3

Multiple Choice

What is the oxidation number of iodine in KIO₃?

• 0

• -1

• +5

• +1

Multiple Choice

What is the oxidation number of chlorine in HClO?

• 0

• -1

• +1

• +5

Multiple Choice

What is oxidation number of Mn in MnO₂ ?

• 0
• +2
• -2
• +4

Multiple Choice

What is the oxidation of C in CH₄?

• -4
• -1
• +4
• +1

Multiple Choice

What is the oxidation number of N in NO₂^1- ?

• -3
• +4
• -2
• +3

Multiple Choice

What is the oxidation number of O in CO₂?

• +2
• -1
• +4
• -2

Multiple Choice

What is the oxidation number of Fe in FeO?

• +1
• -1
• +2
• -2

Multiple Choice

What is oxidation number of P in K₃PO₄?

• +1
• +5
• -2
• 0

Multiple Choice

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

• -2
• +2
• +6
• +12

Multiple Choice

What element is being Reduced?

• N
• H
• O
• S

Multiple Choice

What element is being Oxidized?

• N
• H
• O
• S

Multiple Choice

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

• Zinc
• Hydrogen
• Oxygen
• None

Multiple Choice

In the reaction
2Ca(s) + O₂(g) --> 2CaO(s), calcium is __________

• Reduced
• Synthesized
• Oxidized
• None of the above

Multiple Choice

Is calcium oxidized or reduced in the following reaction? 
2CaO--> 2Ca + O₂

• Oxidized
• Reduced

Multiple Choice

What is a half-reaction of this equation, Na + Cl --> NaCl ?

• Cl + e^- --> Cl^-

• Cl - e^- --> Cl^-

• Na --> Na + e^-

• Na° + Cl°--> Na⁺¹Cl^-1

Multiple Choice

A decrease in oxidation number.

• concentrated

• reduction

• oxidation

• dilute

Multiple Choice

An increase in oxidation number.

• more acidic

• reduction

• less basic

• oxidation

Multiple Choice

Cl₂ + 2e- --> 2Cl ^- is an example of:

• a chemical reaction

• redox

• oxidation

• reduction

Multiple Choice

Which half-reaction correctly represents reduction?

• Ag --> Ag⁺ + e^-

• F₂ --> 2 F^- + 2e^-

• Au³⁺ + 3e^- --> Au

• Fe²⁺ + e^- --> Fe³⁺

Multiple Choice

In a Galvanic cell, the anions from the salt bridge flow towards;

• anode

• cathode

• both electrodes

Multiple Choice

Reactions in galvanic cells are

• spontaneous, redox reactions

• non-spontaneous, redox reactions

• spontaneous, non-redox reactions

• non-spontaneous, non-redox reactions

Multiple Choice

Consider the galvanic cell given.
Which of the following deductions about this cell is correct?

• Oxidation is occurring in half-cell 2
• The positive electrode is in half-cell 2
• Oxidation is occurring in half-cell 1
• The negative electrode is in half-cell 1

Multiple Choice

A certain galvanic cell has for its spontaneous cell reaction: Zn + HgO → ZnO + Hg

Which is the half-reaction occurring at the anode?

• HgO + 2 e- → Hg + O^2-

• Zn²⁺ + 2 e- → Zn

• Zn → Zn²⁺ + 2 e-

• ZnO + 2 e- → Zn

Multiple Choice

In a Galvanic Cell, the salt bridge...

• completes the circuit so that electrons can flow through the wire

• maintains charge balance

• is soaked in an unreactive electrolyte such as KNO₃

• all of the above

Multiple Choice

In a Galvanic cell, the electrons flow from the...

• anode to the cathode

• cathode to the anode

Multiple Choice

Oxidation occurs at the...

• anode

• cathode

Multiple Choice

In a Galvanic Cell, the anode is...

• positive

• negative

Multiple Choice

In a voltaic cell, the salt bridge is necessary for

• the movement of electrons to create a current
• the movement of ions to create a current
• the movement of electrons to maintain the neutrality of solution
• the movement of ions to maintain the neutrality of solution

Multiple Choice

Which energy conversion shown below takes place in a galvanic cell?

• Electrical to chemical

• Mechanical to chemical

• Mechanical to electrical

• Chemical to electrical