18: Chemical Cells in Daily Life Flashcards
What is the definition of a chemical cell?
A chemical cell is a device that converts the chemical energy stored in it into electrical energy.
List the basic components of a chemical cell.
Negative electrode, positive electrode, electrolyte
What is the definition of the negative electrode?
It is the electrode from which electrons flow into the external circuit.
What is the definition of the positive electrode?
It is the electrode into which electrons flow into the external circuit.
What is the definition of electrolyte in a chemical cell?
It is a medium which allows ions to flow between the two electrodes.
What is the direction of flow of electrons when a light bulb is connected to a chemical cell?
The electrons flow from the negative electrode to the positive electrode in the external circuit.
In which situation is the voltage displayed in the digital multimeter positive?
A positive voltage is displayed when the positive electrode of the chemical cell is connected to its positive terminal and the negative electrode of the chemical cell is connected to its negative terminal.
In which situation is the voltage displayed in the digital multimeter negative?
A negative voltage is displayed when the negative electrode of the chemical cell is connected to its positive terminal and the positive electrode of the chemical cell is connected to its negative terminal.
What are the types of chemical cells?
Primary cells which cannot be recharged, and secondary cells which can be recharged.
List 3 types of common primary cells.
Zinc-carbon cell, alkaline manganese cell, silver oxide cell
List 3 types of common secondary cells.
Lead acid accumulator, nickel metal hydride (NiMH) cell, lithium ion cell
What is the definition of cell capacity?
Cell capacity is measured in ampere-hours, which is the number of hours a cell can supply a particular amount of electric current.
What is the definition of energy density?
Energy density is the amount of energy that can be derived per unit volume of the cell.
What is the definition of service life?
Service life is the length of time a cell can remain in use before its voltage drops to a certain value.
What is the definition of cycle life?
Cycle life is the number of charge-discharge cycles a secondary cell can undergo before its capacity falls to 80% of its original value.
What is the definition of shelf life?
Shelf life is the length of time a cell can be stored inactive before its capacity falls to 90% of its original value.
What is the material of the negative electrode of a zinc-carbon cell?
Zinc metal
What is the material of the positive electrode of a zinc-carbon cell?
Carbon
What is the material of the electrolyte of a zinc-carbon cell?
A moist paste of ammonium chloride
What is the material of the negative electrode of an alkaline manganese cell?
Zinc metal
What is the material of the positive electrode of an alkaline manganese cell?
Manganese(IV) oxide