Electrolytic Cell

Which statement describes one characteristic of an operating electrolytic cell?

• It produces electrical energy.

• It requires an external energy source.

• It uses radioactive nuclides.

• It undergoes a spontaneous redox reaction.

Answer explanation

An operating electrolytic cell requires an external energy source to drive the non-spontaneous reactions. This distinguishes it from galvanic cells, which generate electrical energy from spontaneous reactions.

Tags

NGSS.HS-PS3-1

Which device requires electrical energy to produce a chemical change?

• electrolytic cell

• salt bridge

• voltaic cell

• voltmeter

Answer explanation

An electrolytic cell requires electrical energy to drive a non-spontaneous chemical reaction, producing a chemical change. In contrast, a voltaic cell generates electricity from spontaneous reactions, while a salt bridge and voltmeter do not produce chemical changes.

Tags

NGSS.HS-PS2-5

Which process requires energy to decompose a substance?

• electrolysis

• neutralization

• sublimation

• synthesis

Answer explanation

Electrolysis is the process that requires energy to decompose a substance, typically using electrical energy to break down compounds into their elements. The other processes listed do not require energy in the same way.

Tags

NGSS.HS-PS1-4

Which energy conversion must occur in an operating electrolytic cell?

• electrical energy to chemical energy

• electrical energy to nuclear energy

• chemical energy to electrical energy

• chemical energy to nuclear energy

Answer explanation

In an electrolytic cell, electrical energy is converted into chemical energy to drive non-spontaneous reactions. This is essential for processes like electrolysis, making 'electrical energy to chemical energy' the correct choice.

Which statement describes electrolysis?

• Chemical energy is used to produce an electrical change.

• Chemical energy is used to produce a thermal change.

• Electrical energy is used to produce a chemical change.

• Thermal energy is used to produce a chemical change.

Answer explanation

Electrolysis involves using electrical energy to drive a non-spontaneous chemical reaction, resulting in a chemical change. This distinguishes it from other processes that involve thermal or chemical energy.

Tags

NGSS.HS-PS3-5

For which chemical reaction must an electrolytic cell be used?

• AgNO3 + NaCl → AgCl + NaNO3

• Cu + FeCl2 → CuCl2 + Fe

• Zn + 2 HCl → ZnCl2 + H2

• 2 Al + 3 Ni(NO3)2 → 2 Al(NO3)3 + 3 Ni

Answer explanation

The reaction Cu + FeCl2 → CuCl2 + Fe requires an electrolytic cell because it involves the reduction of Fe ions and oxidation of Cu, which cannot occur spontaneously and needs external energy.

Tags

NGSS.HS-PS2-5

In an electrolytic cell, the positive electrode is the

• anode, where oxidation occurs

• anode, where reduction occurs

• cathode, where oxidation occurs

• cathode, where reduction occurs

Answer explanation

In an electrolytic cell, the anode is the positive electrode where oxidation occurs. This is the opposite of a galvanic cell, where the anode is negative. Therefore, the correct choice is 'anode, where oxidation occurs'.

In an electrolytic cell, a negative ion will migrate to and undergo oxidation at the

• anode, which is negatively charged

• anode, which is positively charged

• cathode, which is negatively charged

• cathode, which is positively charged

Answer explanation

In an electrolytic cell, the anode is positively charged. Negative ions migrate to the anode to undergo oxidation, as oxidation occurs at the anode, not the cathode, which is negatively charged.

Tags

NGSS.HS-PS2-5

Where is Na(ℓ) produced in the cell?

• at the anode, where oxidation occurs

• at the anode, where reduction occurs

• at the cathode, where oxidation occurs

• at the cathode, where reduction occurs

Answer explanation

Na(ℓ) is produced at the cathode during reduction, where electrons are gained. This process contrasts with the anode, where oxidation occurs and electrons are lost.

Tags

NGSS.HS-PS2-5

During the electrolysis of fused NaCl, which half-reaction occurs at the negative electrode?

• Na+ + 1e– → Na0

• Na0 → Na+ + 1e–

• 2 Cl– → Cl2 + 2e–

• Cl20 + 2e– → 2 Cl–

Answer explanation

During electrolysis of fused NaCl, Na+ ions gain electrons at the negative electrode (cathode) to form sodium metal. Thus, the correct half-reaction is Na+ + 1e– → Na0.

Tags

NGSS.HS-PS1-2