Question | Answer |
What is another word for a battery? | A cell |
What does a cell (battery) contain? | A cell contains chemicals which react to make electricity |
What is the energy change in a cell? | Chemical Energy to Electrical Energy |
What is a dry cell? | One of the most common batteries. A dry cell's electrolytes are contained in a low-moisture paste. |
What are the components of a dry cell? | At the center of each dry cell is a rod called a cathode, which is made of metal or graphite and is surrounded by an electrolyte paste. The cathode and electrolyte paste are wrapped in paper or cardboard. One or more of these cells are sealed into a metal |
What is the paste in a dry cell used as? | The paste is used as an electrolyte which completes the circuit. |
What is the difference between a dry cell and a wet cell battery? | A dry cell battery is different from a wet cell battery because its electrolytes are contained in a low-moisture paste. A wet cell battery's electrolytes are contained in a liquid. |
Will a dry cell provide electricity forever? | No, eventually the reactants in the cell which are needed to produce electricity will be used up. |
What is a rechargeable cell? | A rechargeable cell is a cell in which the chemicals are not used up and can be regenerated by recharging the cell. |
What is the energy change in a rechargeable cell when the cell is being used (discharging)? | Chemical Energy to Electrical Energy |
What is the energy change in a rechargeable cell when the cell is being recharged? | Electrical Energy to Chemical Energy |
Name the battery in a car | The Lead-Sulphuric acid battery |
How is the Lead-Sulphuric acid battery charged? | It is charged using electricity and a brown coating appears on the positive lead plate. |
What happens when the charger of a Lead-Sulphuric acid battery is removed and replaced with a bulb? | The bulb Lights |
What happens to the bulb over time? | Gradually the bulb dims as the chemical energy in the brown coating is used up and the cell is discharged |
What is Electricity? | Electricity is a flow of moving charged particles which can be electrons or ions |
How is electricity produced? | Electricity is produced when two different metals are dipped in an electrolyte and connected with a wire |
What happens to the electrons and ions when Electricity is produced? | There is a flow of electrons in the wire from one metal to the other, and ions move through the electrolyte |
What happens when two different metals are joined together to produce electricity in a cell? | Electrons always flow through the wire from the metal higher in the ECS to the metal lower in the ECS |
When will a displacement reaction happen? | A displacement reaction will happen when a metal higher in the ECS is added to a solution containing a metal lower in the ECS. The metal which is lower in the ECS is displaced |
What is an ammeter used for in a cell? | The ammeter will show a flow of electrons throw the wire between two metals- the direction of the flow is always from the metal higher in the ECS to the metal Lower in the ECS |
What is the purpose of the ion bridge in a cell? | The ion bridge is needed to complete the circuit by allowing ions to move |
What will happen if the ion bridge is removed from a cell? | The current will stop flowing through the ammeter |
What is the problem with using Lithium in a Lithium cell? | Lithium is a very reactive metal with water so the electrolyte has to be non-aqueous. Also, lithium is expensive |
What was eventually used as an electrolyte in the Lithium cell? | Lithium salts in an organic solvent |
For how long can the Lithium cell run? | 15-20 years |
To be used in the human body, what three features must a cell have? | 1. Has to be long life
2. Has to be non-toxic
3. Has to be unreactive |
What can the Lithium cell be used for? | Artificial Pacemakers |
What is the Nickel-Cadmium cell used for? | Used in toys and other things |
What advantage does the Nickel-Cadmium cell have? | More difficult to damage than other batteries. Also, this cell is rechargeable |
What disadvantage does the Nickel-Cadmium cell have? | Nickel and Cadmium are very expensive metals |
Why must the correct voltage be used to recharge the Nickel-Cadmium cell? | Too high a voltage could cause it to overcharge which can be dangerous |
What environmental disadvantage does the Nickel-Cadmium cell have? | Cadmium is a poisonous metal and can't be put into a landfill |
What comparison can be made about the portability in batteries and mains electricity? | Batteries are much more portable than mains electricity |
What comparison can be made about the cost in batteries and mains electricity? | Mains electricity is cheaper than batteries |
What comparison can be made about the safety in batteries and mains electricity? | Batteries are safer as they produce a lower voltage than mains electricity |
What comparison can be made about the effect on the environment by batteries and mains electricity? | Both Batteries and mains electricity have environmental impacts. Batteries require a constant supply of metals from the earth's crust, whereas mains electricity requires the burning of fossil fuels and radioactive materials |
What does OIL RIG stand for? | Oxidation is Loss (of electrons)
Reduction is Gain (of electrons) |
What is Oxidation? | The reaction of a metal to form a compound. The loss of electrons by a reactant in any reaction |
What is reduction? | The reaction of a compound to form a metal. The gain of electrons by a reactant in any reaction |
What is meant by the term redox? | In a displacement reaction, the metal is oxidised (loses electrons) while the ions of the other metal are reduced (gains electrons). As both oxidation and reduction occur together, the complete reaction is called a REDOX reaction |
What is meant by voltage? | a measure of the push of electrons between two reactions |
What are the Electrochemical series (ECS)? | A list of reactions in the data book (page 7) which can be used to determine which reactions of a pair is better at pushing electrons onto the other reaction |
What is an electrolyte? | An electrolyte is a substance which contains ions which can move |
How can you tell if a reaction is reduction or oxidation by looking at an equation? | Reduction= Electrons will be on the REACTANT SIDE of the equation
Oxidation= Electrons will be on the PRODUCT SIDE of the equation |