Review Redox

Voltaic cells convert

• mechanical energy in to electrical energy

• potential energy in to electrical energy

• electrical energy in to chemical energy

• chemical energy in to electrical energy

Tags

NGSS.HS-PS3-5

In a voltaic cell the ions flow through the 

• wire
• salt bridge

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

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

• -2

• +2

• +6

• +12

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-1

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

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

Tags

NGSS.HS-PS1-2

This is the half reaction for: 
Sn(s) → Sn⁴⁺(aq) + 4e⁻

• redox
• reduction
• oxidation
• neutralization

Tags

NGSS.HS-PS1-2

Which of the following reactions is balanced by both mass and charge?

• Fe⁺² + Al →Fe + Al⁺³
• Cu + Fe⁺² → Cu⁺¹ + Fe⁺³
• F₂ + Br^- --> F^- + Br₂
• Fe⁺² + 2 Cu --> 2 Cu⁺ + Fe

Which of the following half reactions correctly represents a reduction half reaction?

• Fe →Fe²⁺ + 2e^-

• Pb⁴⁺ + 2e^- →Pb²⁺

• 2O^-2 →O₂ + 4e^-

• Fe + 3e^- →Fe³⁺

Which half-reaction correctly represents reduction?

• Ag --> Ag⁺ + e^-

• F₂ --> 2 F^- + 2e^-

• Au³⁺ + 3e^- --> Au

• Fe²⁺ + e^- --> Fe³⁺

What reaction occurs at the anode?

• Ag⁺ + e^- →Ag
• Ag → Ag⁺ + e^-
• Ni²⁺ + 2e^- → Ni
• Ni → Ni²⁺ + 2e^-

Tags

NGSS.HS-PS2-5