Electrochemistry & Redox Reactions

<p>+4 (A)</p> Signup and view all the answers

<p>-2 (A)</p> Signup and view all the answers

<p>+3 (C)</p> Signup and view all the answers

<p>+2 (C)</p> Signup and view all the answers

<p>0 (A)</p> Signup and view all the answers

<p>Addition of oxygen or removal of hydrogen (D)</p> Signup and view all the answers

<p>PbO (C)</p> Signup and view all the answers

<p>Cu (B)</p> Signup and view all the answers

<p>One substance gains electrons while the other loses (A)</p> Signup and view all the answers

<p>It is oxidized to Zn^2+ ions. (B)</p> Signup and view all the answers

<p>The voltmeter shows a potential difference. (D)</p> Signup and view all the answers

<p>Cl2 (C)</p> Signup and view all the answers

<p>It gains mass. (C)</p> Signup and view all the answers

<p>They require an electrolytic cell to proceed (D)</p> Signup and view all the answers

<p>It balances the charge by allowing ionic flow. (C)</p> Signup and view all the answers

<p>Gain of electrons (A)</p> Signup and view all the answers

<p>It is negatively charged. (C)</p> Signup and view all the answers

<p>Oxidation occurs (A)</p> Signup and view all the answers

<p>It increases. (B)</p> Signup and view all the answers

<p>The flow of electrons ceases. (D)</p> Signup and view all the answers

<p>Cu^2+ (A)</p> Signup and view all the answers

<p>It restores electrical neutrality by allowing ion migration. (D)</p> Signup and view all the answers

<p>Zinc rod. (C)</p> Signup and view all the answers

<p>Oxidation leading to the formation of Zn^2+ ions. (D)</p> Signup and view all the answers

<p>By losing electrons that travel to the copper cathode. (A)</p> Signup and view all the answers

<p>It stops the flow of electrons. (D)</p> Signup and view all the answers

<p>Anions from the electrolyte. (C)</p> Signup and view all the answers

<p>Neutral solutions in both compartments. (C)</p> Signup and view all the answers

<p>Reduction reaction. (B)</p> Signup and view all the answers

<p>1M concentration of ions and 1 atm pressure of gas at 298K (D)</p> Signup and view all the answers

<p>Oxidation occurs at the electrode. (C)</p> Signup and view all the answers

<p>Half cells cannot cause movement of charges by themselves. (D)</p> Signup and view all the answers

<p>Nature of the electrode material (D)</p> Signup and view all the answers

<p>Platinum wire (B)</p> Signup and view all the answers

<p>0 volts (C)</p> Signup and view all the answers

<p>H+ ions are reduced to form hydrogen gas. (A)</p> Signup and view all the answers

<p>Both B and C are correct. (D)</p> Signup and view all the answers

<p>Hydrogen ions are converted to hydrogen gas. (B)</p> Signup and view all the answers

<p>The cathode is connected to the negative terminal. (B)</p> Signup and view all the answers

<p>Chlorine gas. (A)</p> Signup and view all the answers

<p>Galvanic cells are connected by a salt bridge. (C)</p> Signup and view all the answers

<p>2Na+ + 2Cl- + 2H2O → 2Na+ + 2OH- + H2 + Cl2 (B)</p> Signup and view all the answers

<p>It produces equal amounts of H+ and OH- ions. (A)</p> Signup and view all the answers

<p>Oxidation of metals releases electrons to the solution. (D)</p> Signup and view all the answers

<p>It liberates hydrogen gas and chlorine gas. (D)</p> Signup and view all the answers

Loss of electrons by an atom or group of atoms.

Gain of electrons by an atom or group of atoms.

A chemical reaction involving both oxidation and reduction.

Substance causing oxidation (accepting electrons).

Substance causing reduction (donating electrons).

Device transforming chemical energy to electrical energy, or vice-versa.

Electrochemical cell producing electrical energy from a spontaneous redox reaction.

Electrochemical cell using electrical energy to drive a non-spontaneous redox reaction.

A device that converts chemical energy into electrical energy through a redox reaction.

Loss of electrons by a substance.

Gain of electrons by a substance.

Electrode where oxidation occurs.

Electrode where reduction occurs

Completes the circuit in a voltaic cell by allowing ion flow but preventing direct mixing of the solutions.

Electrons flow from the anode to the cathode

A type of electrochemical cell that produces electrical energy from a spontaneous redox reaction. Also known as Galvanic cell.

An electrochemical cell utilizing the zinc-copper sulfate redox reaction to generate an electric current.

A component in an electrochemical cell that maintains electrical neutrality by allowing ion migration between the half-cells.

A device that converts chemical energy into electrical energy through a redox reaction.

The electrode where oxidation occurs in an electrochemical cell.

The electrode where reduction occurs in an electrochemical cell.

A chemical reaction involving both oxidation and reduction.

Either the oxidation or reduction part of a redox reaction.

A substance that conducts electricity when dissolved in a solution.

The oxidation number of an element in its free state (uncombined form) or molecular form is always zero.

The oxidation number of an element forming a monoatomic ion is equal to the charge on the ion.

The oxidation number of fluorine (F) in compounds is always -1.

The oxidation number of oxygen (O) in most compounds is -2, except in peroxides (like H2O2) where it's -1, and in compounds with fluorine where it can be positive.

The oxidation number of an element is a number assigned to it to trace the movement of electrons in a chemical reaction. In a molecule, the sum of the oxidation numbers of all the atoms must be zero. If the structure is a polyatomic ion the sum of the oxidation numbers equals the charge.

In a neutral molecule such as H2S2O7 the sum of the oxidation numbers of atoms is zero, the oxidation number of hydrogen is +1, oxygen +2, which when substituted into the equation allows to obtain that the oxidation number of Sulfur is +6.

In a polyatomic ion the sum of the oxidation numbers of the atoms is equal to the ion charge. Therefore, in HSO3⁻ the sum is -1. The oxidation number of Hydrogen is +1 and oxygen +2, which allows to calculate the oxidation number of Sulfur is +4.

When two dissimilar atoms share electrons, the shared pair of electrons is counted towards the more electronegative atom. This results in a negative oxidation number for the more electronegative atom and positive for the less electronegative.

The tendency of a chemical species to gain electrons and be reduced.

The tendency of a chemical species to lose electrons and be oxidized.

The potential of an electrode when the concentrations of reacting species are 1 M and the temperature is 298 K. Measured relative to the standard hydrogen electrode (SHE).

The reference electrode whose electrode potential is arbitrarily set to zero (0.00 V).

Nature of electrode material, concentration of metal ions in solution, temperature, and valency.

Electrode potentials are measured in volts.

By IUPAC, electrode potentials are expressed with the perspective of reduction.

An electrode material that does not participate in the redox reaction at the electrode.

The electrode connected to the negative terminal of a cell during electrolysis.

The electrode connected to the positive terminal of a cell during electrolysis.

Using electricity to drive a chemical reaction involving the dissociation of sodium chloride and water; forming hydrogen gas at the cathode and chlorine gas at the anode.

An electrochemical cell that uses electrical energy to power a non-spontaneous chemical reaction.

An electrochemical cell that produces electrical energy from a spontaneous chemical reaction.

Both electrodes are in the same container (solution)

Hydrogen gas (H2) is produced at the cathode during electrolysis of aqueous sodium chloride solution.

Chlorine gas (Cl2) is produced at the anode during electrolysis of aqueous sodium chloride solution.