Unit D Section 1.4 Flashcards
(24 cards)
What is a pacemaker?
A pacemaker is an is an implanted device that delivers a small amount of current at regular intervals to keep the heart beating normally for people who have problems with heart beating.
What is an electrochemical cell?
An electrochemical cell is Cells that contain chemicals to produce a steady current/electricity.
Chemical reactions produce small amounts of current.
What are the two main cells:
Dry cell
Wet cell
What are dry cells:
They are called dry because chemicals are in paste or powder.
Can be used in things such flashlight and radios
What is the process of dry cells?
The chemicals in the cell release free electrons through the negative terminal and then through the device and back in the cell through the positive terminal.
The most common dry cell is
Alkaline cells have become the most common type of dry cell.
Structure of a cell:
A cell is simply two different metals in an electrolyte.
The electrolyte reacts with the two metals, called electrodes.
As a result of this reaction, one electrode becomes positively charged, and the other becomes negatively charged. These electrodes are connected to the cell’s terminals
electrolyte
An electrolyte is a paste or liquid that conducts electricity because it contains chemicals that form ions.
Ions
Ions n is an atom or a group of atoms that has become electrically charged through the loss or gain of electrons from one atom to another.
In a dry cell which terminal do electrons leave?
In a dry cell, electrons leave from the negative electrode, and return to the positive electrode.
What are Wet cells:
A wet cell uses a liquid electrolyte that is usually an acid, such as sulfuric acid.
The acidic electrolyte gradually eats away the zinc electrode. But is often replaced. This process leaves behind electrons that give the slowly disappearing electrode a negative charge
Electrons travel along the wire from the negative zinc electrode to the positive copper electrode. They provide energy
WHich is the zinc electrode and which is the copper?
zinc= negative electrode copper= positive electrode
Drawbacks of a cell:
and the solution
Cells tend to be heavy and rigid.
Solution: make cells out of plastic.
primary cell
Primary cells are cells that produce electricity from chemical reactions that cannot be recharged or reversed.
Are dry cell and wet cell primary or secondary cells?
Dry cells and wet cells are considered primary cells.
Secondary cells
ALso known as rechargable cell:
Secondary cells are rechargeable cells.
A rechargeable cell can be reversed by using an external electrical source to run electricity back through the cell. This is when electrons flow is reversed and restores the reactants that are used up when the cell produces electricity.
What are secondary or rechargeable cells used for?
They can be used to operate cell phones and laptops.
combination of chemicals often used in secondary cells:
Nickel oxide and cadmium
This process does not reform the electrodes perfectly and rechargeable cells wear out eventually.
What is a battery?
Connecting cells together creates a battery
Most batteries are sealed into cases with only two terminals
Electrochemistry:
study of chemical reactions involving electricity.
Branch of science that deals with the study of electricity and the chemicals that produce electricity
What is electrolysis?
Electro= electricity Lysis= breakdown
Using electricity we can separate useful elements from a compound
Ex. Electrolysis of water produces the fuel for the space shuttle. The water molecules are separated into pure hydrogen and oxygen. When these two gases are mixed and ignited, they release a tremendous amount of energy, making these two elements a powerful rocket fuel.
What is electroplating?
A technique of covering an inexpensive metal with an expensive metal by passing electricity
Ex. Gold trophy or spoons, cheaper metal is stronger too.
Process of electroplating?
The item to be coated and a bar of the coating metal are immersed in an electrolyte, like the electrodes in a wet cell. A source of electricity is connected between the two metals. The flow of electricity through the electrolyte deposits atoms from the positively charged metal onto the negatively charged one. Electroplating is often used to protect metals from corrosion.
Other electro things:
Anodizing and electrorefining are two more examples of electrochemical
Anodizing is a process to coat aluminum parts with a layer of aluminum oxide.
Electrorefining can be used to remove impurities from metal.
. For example, impure gold can be formed into bars that serve as an electrode in an electrolytic cell.
