As the cell runs, only copper produces ions. Silver actually loses ions from solution. If this continues without balance by the salt bridge, the positive ions build up in the solution on the left side of the diagram, without any balanced negative ions, and repel the formation of new copper ions more and more strongly.

There must be  pre-existing in the right-side half reaction for the cell to function at all. Without the pre-existing ions, the cell has no electron acceptor dissolved in solution, and no electron transfer can therefore take place. Electron transfer is the fundamental energy-producing process that takes place in a voltaic cell.

Structure "X" corresponds to the slat bridge. Its main function is balancing the ionic charge that builds up as a voltaic cell functions; therefore, there needs to be an ability for the salt bridge to ionize and send appropriate ions to each half cell. KOH is the only ionizable salt among the answer choices.

Potassium ions (K⁺) will be positively charged, which means they will travel towards the side of the cell that is more negative. Reduction takes place at the cathode, because electrons flow from the anode to the cathode. Since negative charge accumulates at the cathode, the cations will travel in that direction, while the anions will travel towards the anode.

This problem requires us to use dimensional analysis in order to compare what we know, and arrive at the current of the cell. First, we start by noting that the unit for current is Coulombs per second, or . Next, we combine the details of the galvanic cell in order to arrive at the appropriate units, and determine the current.

A single battery can act as both a galvanic and an electrolytic cell. When a battery is discharging it is considered to be a galvanic cell because it is undergoing a spontaneous redox reaction and is losing voltage. On the other hand, when a battery is charging, it is acquiring voltage (from the phone charger that is connected to an outlet) and is considered an electrolytic cell.

Recall that electrolytic cells facilitate nonspontaneous reactions and require energy to carry out these unfavorable reactions. Charging a battery is a nonspontaneous process (because the reaction involved is the reverse of the reaction that occurs when the battery is discharging) and requires energy in the form of voltage input.

Faraday’s Law states that the amount of substance produced in a half-cell is dependent on the charge applied to the system; therefore, the more charge applied the more substance produced. The question states that the researcher applies the same amount of current, but for a shorter time, in trial 2. Recall the definition of current:

This means that charge equals:

Trial 1 and Trial 2 have the same current; however, trial 2 has a smaller time. This means that the charge applied in trial 2 is smaller than the charge applied in trial 1; therefore, according to Faraday’s law, the researcher must observe a smaller mass of zinc metal in trial 2.

Faraday’s Law states that the amount of product in a half cell is proportional to the charge applied to the cell; therefore, the amount of product in a cell increases as the charge increases. Faraday’s Law states nothing about the relationship between the amount of product and time.

The question asks you to pick substances that cannot conduct electricity. Recall that molecules that conduct electricity in solution are called electrolytes. In a chemical solution, a substance will conduct electricity if it can dissociate into ions; therefore, you are looking for molecules that will not dissociate into ions in water.

Sodium chloride, or , is an ionic compound that will dissociate into sodium ions and chlorine ions; therefore, sodium chloride will conduct electricity in water.

Iron (II) carbonate  is an insoluble compound in water. This means that it will not dissociate into ions and will not conduct electricity. Remember that most carbonates are insoluble in water.

Glucose is soluble in water because of its polar hydroxyl groups; however, it does not dissociate into ions. This means that glucose does not conduct electricity.

Electrical conductivity is a measure of the ability of a substance to conduct electricity. A substance with a high electrical conductivity will easily conduct electricity, and a substance with low electrical conductivity will not conduct electricity.

In solution, a substance can conduct electricity if it can dissociate into ions. Of the three substances listed, hydrochloric acid is likely to have the highest electrical conductivity. Recall that hydrochloric acid () is a strong acid; therefore, it will completely dissociate into hydrogen and chlorine ions in water.

The substance with the second highest electrical conductivity is acetic acid. Although acetic acid is an acid, it is a weak acid. This means that the acetic acid will not completely dissociate into ions in water. If you have the same concentration of hydrochloric acid and acetic acid, hydrochloric acid will produce more ions in water and will be able to conduct more electricity; therefore, hydrochloric acid has a higher electrical conductivity than acetic acid.

Acetone is soluble in water; however, it does not dissociate into ions and will have the lowest electrical conductivity.

The correct order of electrical conductivity is: .