Intermediate 1 Unit 2 Batteries & Personal Needs
How is electricity produced in a battery? Chemicals react
Why do batteries go flat? The chemicals are used up.The chemical reaction stops.
Give an example of a rechargeable battery. Car battery (lead-acid battery)
What is the purpose of the ion solution? To complete the circuit
How is the voltage related to the reactivity of the metals connected in the cell? (Use data booklet) The further away from each other in the reactivity series the higher the voltage.
Which cell will have the highest voltage - a magnesium/zinc cell or a magnesium /copper cell? Magnesium/copper cell.
Why is soap needed to clean oil and grease off clothes, skin and hair. Oil and grease are insoluble in water
How are cleaning chemicals able to break up the oil and grease which can then mix with water? They are soluble in both water and oil/grease.
Give an example of a cleaning chemical. Soap, detergents, shampoo, washing-up liquids and powders.
What type of detergent is used to form a lather with hard water? A soapless detergent
What is formed when some soaps are used with hard water? A scum
What is special about the solvents used in dry-cleaning? They are very good at dissolving oil and grease stains.
What are the thin strands called which are used to make clothing fabrics? Fibres
What do natural fibres come from? Plants and animals
What type of fibres are made by the chemical industry? Synthetic fibres
Give three examples of a natural fibre? Wool, silk, cotton
Name two synthetic fibres. Nylon and polyester
What are the long chain molecules which make up a fibre called? Polymers
What are dyes used for? To give bright colours to clothing
Some fibres are hard to drip dry. Do these fibres form strong or weak bonds with water? Strong bonds
Why do some fibres not feel sweaty to wear? They soak up perspiration
A cell is made by connecting zinc metal and copper metal in a solution. What would happen to the voltage of the cell if the zinc was replaced with tin ? It would go down
A cell is made by connecting zinc metal and copper metal in a solution. What would happen to the voltage of the cell if the copper was replaced with silver ? It would go up.
Give an advantage of using batteries rather than mains electricity. Batteries are portable
Give a disadvantage of using batteries rather than mains electricity. They run out. They are more expensive than mains electricity.
Why are some fabrics flameproofed? To stop them catching fire easily
Name the type of battery used in a car? Lead-acid battery
Intermediate 1 Unit