Question

One of the most useful applications of oxidation-reduction reactions is the production of electricity. Batteries are “prepackaged” redox reactions which produce electricity. Consider the redox reaction of aluminum metal reacting with vinegar (acetic acid). 2 Al + 6 HC2H3O2 º 2 Al(C2H3O2 )3 + 3 H2 or 2 Al + 6 H+ º 2 Al3+ + 3 H2 A battery works by physically separating the oxidation and the reduction half reactions.

Why does the cardboard need to be soaked in the vinegar solution?

It makes the cardboard taste better.

The battery must have an electrolyte to allow the flow of electrons and cations.

The acetic acid won't react with copper,

The acetic acid provides the hydrogen (H+) for the reaction to occur.

Look at the reaction. Salt is not part of the reaction, and yet it is added to the vinegar in step 2. What is the purpose of the salt?

It makes the cardboard taste better.

The battery must have an electrolyte to allow the flow of electrons and cations.

The salt won't react with copper.

One battery consists of a piece of aluminum, a penny, and a piece of soaked cardboard stacked on top of each other, in that order..

True

False

Look at the half reactions on the Activity Sheet. The aluminum is oxidized (loses or produces electrons), while simultaneously the hydrogen is reduced (consumes electrons). How many moles of electrons are produced (and consumed) in this balanced reaction?

6 moles of electrons for every 2 moles of Al

6 moles of electrons for every 3 moles of H2 produced.

Both are correct

Neither are correct

What is the copper penny used for in the battery?

The copper provides the Cu2+ ions for the reaction

The copper serves as the cathode to allow the flow of electrons from the anode.

Abraham Lincoln is very electric

No answer text provided.

Why must the cardboard be soaked in the vinegar/salt solution?

To provide a porous disk with electrolyte solution enabling the battery to operate.

To provide the electrolyte solution to enable the battery to operate

To provide a snack for hungry students

Two of the answers are correct

There is no correct answer

How does the number of batteries affect the amount of light emitted?

More batteries gives less light

More batteries gives more light

How many batteries were required to observe light?

What other solutions might be used with this battery? (Choose the best answer)

Citric acid

Hydrochloric acid

Any weak acid that does not react with aluminum or copper

Answer 1

The cardboard need to be soaked in the vinegar solution as The battery must have an electrolyte to allow the flow of electrons and cations.

The purpose of the salt is The battery must have an electrolyte to allow the flow of electrons and cations.

One battery consists of a piece of aluminum, a penny, and a piece of soaked cardboard stacked on top of each other, in that order..TRUE

The number moles of electrons are produced (and consumed) in this balanced reaction

6 moles of electrons for every 2 moles of Al and 6 moles of electrons for every 3 moles of H₂ produced.

Both are correct

The copper penny used for in the battery as The copper serves as the cathode to allow the flow of electrons from the anode.

The cardboard must be soaked in the vinegar/salt solution as it provide the electrolyte solution to enable the battery to operate.

Number of batteries affect the amount of light emitted as More batteries gives more light.

More than 5 batteries were required to observe light

Solutions might be used with this battery Any weak acid that does not react with aluminum or copper