A level electrochemical cells

he standard redox potentials for a number of substances are shown below:
F₂(g) + 2e^-→ 2F^-(aq); E⁰ = 2.87 V
O₂(g)+ 4H⁺(aq)+ 4e^-→  2H₂O(l);  E⁰ = 1.23 V
Cu²⁺(aq) + 2e^-→  Cu(s); E⁰ = 0.34 V
Fe²⁺(aq) + e^- → Fe(s); E⁰ = -0.41V
2H₂O(l) + 2e^- →  H₂(g) + 2OH^-(aq);  E⁰ = -0.83 V
Mg²⁺(aq) + 2e^- →  Mg(s); E⁰ = -2.38 V
If all of these substances were available, what galvanic cell could be set up using these substances that would steadily deliver approximately 1.6 V?

• F₂/F^- and O₂/H₂O
• O₂/H₂O and Fe²⁺/Fe
• O₂/H₂O and Cu²⁺/Cu
• H₂O/H₂ and Mg²⁺/Mg

The cell reaction occurring in a particular button cell was:
Zn(s) + Ag₂O(s) + H₂O(l) →  2Ag(s)+   Zn(OH)₂(s)
This cell delivered 1.50 V. The half-equation for the silver half-cell is:
Ag₂O(s)+ H₂O(l)+ 2e^-→  2Ag(s)+ 2OH^-(aq);  E⁰ = 0.34 V
The standard redox potential for the zinc half-cell must be:

• -1.16 V
• +1.16 V
• -1.84 V
• +1.84 V

What is the key difference between a galvanic cell and a fuel cell? 

• Galvanic cells deliver direct current; fuel cells deliver alternating current. 
• Galvanic cells are essentially for energy storage; fuel cells work continuously. 
• Galvanic cells do not use gases as reactants; fuel cells only use gases. 
• Galvanic cells are not rechargeable; fuel cells are constantly recharged.

A galvanic cell is established to power a torch, as shown.
For this cell, the

• electrons will flow from the aluminium to the hydrogen half-cell
• aluminium electrode will be the positive anode
• concentration of aluminium ions in solution will be falling
• hydrogen half-cell will be the negative cathode

Tags

NGSS.HS-PS1-2

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

Tags

NGSS.HS-PS2-5

A fuel cell can be constructed that uses the two half-reactions as shown.
Which one of the following would occur at the negative electrode of the cell as it generates electricity?

• production of H⁺
• formation of H₂O
• consumption of CO₂
• reduction of CH₃OH

A fuel cell can be constructed that uses the two half-reactions as shown.
Which one of the following statements about this fuel cell is most likely to be correct?

• An external power supply is used to recharge the cell.
• Gaseous products are recycled into the cell to improve efficiency.
• Chemical energy is not completely converted into electrical energy.
• More H⁺ ions are produced at the anode than are consumed at the cathode.

Which one of the following state is true for both fuel cells and rechargeable cells?

• All reactants are stored within the cell.
• Reaction products are continuously removed from the cell.
• Electrons pass from the reductant to the anode as electricity is produced.
• Electrical energy is converted to chemical energy as the cell is recharged.

What happens to oxygen molecules in a hydrogen-oxygen fuel cell?

• They react with electrons to form oxide ions, O^2-

• They react with hydrogen ions to form hydroxide ions, OH^-

• They react with hydrogen ions and electrons to form water

What is the main reason why hydrogen is more difficult to store than diesel?

• Hydrogen is a gas at room temperature but diesel is a liquid

• Hydrogen can be liquefied by cooling it

• Hydrogen can be stored under pressure