Unit 8: Chemistry
Balance the equation using the ion-electron method: Aqueous sodium stannite reacts with solid bismuth(III) hydroxide to produce bismuth metal, aqueous sodium stannate, and water. The solution is basic.
3Na2SnO2 +2Bi(OH-)3 → 2Bi+3Na2SnO32-+3H2O
Use Table B-18 to predict whether the reactants in the following problems would produce the products shown: LiNO3(aq) + Ag(s) → AgNO3(aq) + Li(s)
No, Ag will not reduce the Li+ as Ag is higher than Li+. Redox should not happen.
Use Table B-18 to predict whether the reactants in the following problems would produce the products shown: 2NH4Cl(g) + I2(g) → 2NH4I(g) + Cl2(g)
No, Cl- will not reduce the I2 as Cl- is higher than I2. Redox should not happen
__________ is the process in which an atom or ion experiences an increase in its oxidation state.
Oxidation
secondary voltaic cell
a "rechargeable" electrochemical cell that produces electric current by reversible redox reactions
salt bridge
a U-shaped glass tube containing an aqueous salt solution that is used to create a "bridge" for ions to pass between the two half-cells of a voltaic cell
ionic equation
a chemical equation in which any compound that could ionize is written as separate ions and which includes the oxidation number for each element in the equation
battery
a combination of two or more voltaic cells connected to work together
electrochemical cell
a device that converts chemical energy to electric current or that uses electrical energy to cause a chemical reaction
electrical potential
a measure of the amount of current that can be generated by a voltaic cell to do work
standard hydrogen electrode
a reference hydrogen electrode with its reduction potential set to zero that is used to determine all other electrode reduction potentials
oxidizing agent
a substance that has the potential to cause oxidation in another substance
reducing agent
a substance that has the potential to cause reduction in another substance
fuel cell
an electrochemical cell that produces electric current by oxidation of a fuel
primary voltaic cell
an electrochemical cell that produces electric current by redox reactions that are not reversible
voltaic cell
an electrochemical cell that uses a spontaneous redox reaction to convert chemical energy into electrical energy
An alkaline cell lasts longer than a zinc-carbon cell of the same size because there is a greater amount of _________ material.
anode
Oxidation takes place at the _________ of a zinc-carbon cell or general-purpose battery.
anode
In an electrochemical cell, the ______ is the electrode where oxidation takes place, and the ______ is where reduction takes place.
anode cathode
The shorthand notation for an electrochemical cell is: anode electrode | ______ solution || cathode solution | cathode _______.
anode electrode
oxidation-reduction reaction
any chemical process in which an atom or ion experiences an increase in oxidation state, which is accompanied by a simultaneous decrease in oxidation state by another atom or ion
Although not technically correct, a voltaic cell is commonly known as a(n) _______.
battery
Reduction takes place at the carbon rod or _________ of a zinc-carbon cell or general-purpose battery.
cathode
The shorthand notation for an electrochemical cell takes into account the composition of the _______ , __________ , and the identities of the ions that are transferred
cathode anode
As zinc atoms oxidize in a zinc-carbon cell, they lose electrons that travel through the electrical circuit and back to the _________.
cathode (carbon rod)
The process in which a substance acts as both an oxidizing agent and a reducing agent in the same reaction is called _______.
disproportionation
When a substance being oxidized in a redox reaction is connected by a conductor to a substance that is being reduced, a(n) ______ current will flow through the conductor.
electric
flow caused when the anode and cathode are joined with a conductor
electric current
A device that converts chemical energy to electrical energy or uses electrical energy to cause a chemical reaction is called a(n) ____________________ cell.
electrochemical
The paste in between the anode and cathode in a zinc-carbon cell or general-purpose battery functions as a(n) _________.
electrolyte
What are three methods for balancing redox equations?
electron-transfer inspection ion-electron
An electrochemical cell that produces an electric current by oxidation of a fuel is called a(n) ______________ cell.
fuel
Electric current will move only from an anode of ______ electrical potential to a cathode with ______ electrical potential.
higher lower
formed when a catalyst in one chamber causes H2 molecules to oxidize
hydrogen
A disadvantage of fuel cells is that:
hydrogen is very explosive
A chemical equation in which any compound that could ionize is written as separate ions and which includes the oxidation number of each element in the equation is a(n) _______ equation.
ionic
spectator ions
ions that are present in an oxidation-reduction reaction but do not participate in oxidation or reduction
The cathode in an alkaline cell is composed of _________.
manganese dioxide
A recharger applies electric current to the cell in the ________ direction of the operational electron flow.
opposite
Oxidation takes place when an atom or ion loses one or more electrons, thereby experiencing an increase in its _______ state.
oxidation
Reduction takes place when an atom or ion gains one or more electrons, thereby experiencing a decrease in its ________ state.
oxidation
The process in which an atom or ion experiences an increase in its oxidation state is __________.
oxidation
If an electric current is applied between some substances, ______ and, ______ will happen.
oxidation reduction
The oxidation component of a redox reaction is called a(n) _____ half-reaction; the reduction component of a redox reaction is called a(n) _____ half-reaction
oxidation reduction
The ______ cell is the portion of an electrochemical cell where oxidation takes place, and the portion where reduction takes place is the ______ cell.
oxidation half- reduction half-
A(n) _________ is any chemical process in which an atom or ion experiences an increase in oxidation state that is accompanied by a simultaneous decrease in oxidation state by another atom or ion.
oxidation-reduction reaction
Any chemical process in which an atom or ion experiences an increase in oxidation state that is accompanied by a simultaneous decrease in oxidation state by another atom or ion, is a(n) ____________________.
oxidation-reduction reaction
When a(n) _________ agent reduces, it causes oxidation in another substance.
oxidizing
A substance called a(n) ______ agent has the potential to cause oxidation in another substance, but a substance with the potential to cause reduction in another substance is a(n) ______ agent.
oxidizing reducing
gas that is pumped into another chamber functioning as the cathode that produces OH- ions
oxygen
An electrochemical cell that produces electric current by redox reactions that are not reversible is called a(n) ______ voltaic cell, but a(n) ______ voltaic cell is an electrochemical cell that produces an electric current by reversible redox reactions.
primary secondary
The region where a chemical reaction occurs when two substances of different states, such as a solid and a liquid, come in contact is called ________ interface
reaction
When a(n) _________ agent oxidizes, it causes reduction in another substance
reducing
The negative ion of a strong oxidizing agent is a weak ______ agent, and the positive ion of a strong reducing agent is a weak ______ agent.
reducing oxidizing
The process in which an atom or ion experiences a decrease in its oxidation state is _____________.
reduction
When you place a strip of copper in an electrolyte solution of zinc sulfate, ________, ____________, and, ___________ occur simultaneously.
reduction oxidation ion exchange
The double line in the shorthand notation indicates a(n) _________ bridge.
salt
For electrons to flow from the oxidation half-cell through a conductor to the reduction half-cell, a(n) ______ bridge must be placed between the two half-cells to allow ______ to pass from one solution to another.
salt ions
A moist paper spacer separating the zinc anode from the electrolyte paste in a zinc carbon cell functions as a(n) _________.
salt bridge
The three types of voltaic cells are primary cells, __________ cells, and _______ cells.
secondary fuel
An unbalanced chemical equation that includes the chemical formulas of the atoms, molecules, and ions in the reaction without coefficients, charges, or oxidation numbers is called a ____ equation.
skeleton
An unbalanced chemical equation that includes the chemical formulas of the atoms, molecules, and ions in the reaction without coefficients, charges, or oxidation numbers is called a(n) ____ equation.
skeleton
Ions that are present in an oxidation-reduction reaction but do not participate in oxidation or reduction are called _________ ions.
spectator
A reference hydrogen electrode with its reduction potential set to zero that is used to determine the reduction potentials of all other half cells is called a(n) __________.
standard hydrogen electrode
electrochemistry
the branch of chemistry that deals with oxidation-reduction reactions that generate electricity and with chemical changes caused by electricity
anode
the electrode where oxidation takes place in an electrochemical cell; the negative electrode in a voltaic cell or battery; the positive terminal in an electrolytic cell; the electrode where electrons are received in an electron tube
cathode
the electrode where reduction takes place in an electrochemical cell; the positive terminal in a voltaic cell or battery; the negative terminal in an electrolytic cell; the electrode where electrons are emitted in an electron tube
voltage
the measure of the difference in electrical potential between two points in a circuit
oxidation half-reaction
the oxidation component of a redox reaction
The oxidation component of a redox reaction is __________.
the oxidation half-reaction
A substance with the potential to cause oxidation in another substance is __________.
the oxidizing agent
oxidation half-cell
the portion of an electrochemical cell where oxidation takes place
reduction half-cell
the portion of an electrochemical cell where reduction takes place
disproportionation
the process in which a substance acts as both an oxidizing agent and a reducing agent in the same reaction
reduction
the process in which an atom or ion experiences a decrease in oxidation state
oxidation
the process in which an atom or ion experiences an increase in oxidation state
A substance with the potential to cause reduction in another substance is __________.
the reducing agent
reduction half reaction
the reduction component of a redox reaction
The reduction component of a redox reaction is __________.
the reduction half-reaction
reaction interface
the region where a chemical reaction occurs when two substances of different states, such as a solid and a liquid, come in contact
reduction potential
the tendency of a half-reaction to occur as a reduction half-reaction in an electrochemical cell
The biggest advantage of fuel cells is that
they don't produce polluting emissions
skeleton equation
unbalanced chemical equation that includes the chemical formulas of the atoms, molecules and ions in the reaction without coefficients, charges, or oxidation numbers
_______ is the measure of the difference in electrical potential between two points in a circuit.
voltage
A(n) _____________ cell is an electrochemical cell that uses a spontaneous redox reaction to convert chemical energy into electrical energy.
voltaic
is produced at the anode interface when H+ ions react with OH- ions
water
Use the electron-transfer method to balance this redox equation: Aluminum metal reacts with hydrochloric acid to produce aluminum III chloride and hydrogen gas.
2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)
The oxidation half-reaction for a fuel cell is :
2H2→4H+ + 4e-.
The reduction half-reaction for a fuel cell is :
2O2+ 2H2O++ 4e-→4OH-
Use the electron-transfer method to balance this equation: Solid antimony reacts with sulfuric acid to produce antimony(III) sulfate, sulfur dioxide and water. The chemical formula for antimony (III) sulfate is Sb2(SO4)3.
2Sb(s) + 6H2SO4(aq) → Sb2(SO4)3(aq) + 3SO2(g) + 6H2O(l)
In the ion-electron method for balancing redox equations you follow the following steps:
Cancel anything that appears on both sides of the equation after it has been balanced and combine the half-reactions to form the compounds in the skeleton equation. Determine which atoms or ions have been oxidized/reduced and write out their oxidation and reduction half reactions. Adjust the numbers of electrons and the coefficients in the half reactions to balance the mass and charge of both half reactions. If necessary, use inspection to adjust the coefficients of atoms or ions that did not undergo oxidation or reduction. Write out the skeleton equation. Rewrite the equation as an ionic equation, eliminate all molecules or ions that do not contain elements that were oxidized or reduced
__________ is the process in which a substance acts as both an oxidizing agent and a reducing agent in the same reaction
Disproportionation
_____________ is the measure of the amount of electric current that can be generated by a voltaic cell to do work.
Electrical potential
_____________ is thought of in terms of reduction potential.
Electrical potential
________ is the branch of chemistry that deals with oxidation and reduction reactions that generate electricity and with chemical changes caused by electricity.
Electrochemistry
In the electron-transfer method for balancing redox equations you follow the following steps:
If necessary, use inspection. Determine which atoms or ions have been oxidized/reduced and write out their oxidation and reduction half reactions. Insert the necessary coefficients into the skeleton equation. Adjust the numbers of electrons and the coefficients in the half reactions to balance the mass and charge of both half reactions. Write out the skeleton equation and assign oxidation numbers to all atoms and ions in the equation.
__________ is the process in which an atom or ion experiences a decrease in oxidation state
Reduction
______________ is the tendency of a half-reaction to occur as a reduction half-reaction in an electrochemical cell.
Reduction potential
Use Table B-18 to predict whether the reactants in the following problems would produce the products shown in a redox reaction: 2Al(s) + 3H2SO4(aq) → Al2(SO4)3(aq) + 3H2(g)
Yes, Al will reduce the H+1 as H+1 is higher than Al. Redox should happen.
Use Table B-18 to predict whether the reactants in the following problems would produce the products shown: Zn(s) + FeSO4(aq) → ZnSo4(aq) + Fe(s)
Yes, Fe2+ will oxidize the Zn as Fe2+ is higher than Zn. Redox should happen.
