Fichas
C2
Fichas del conjunto (22)
- 1What are the properties of a material?Melting point - Temperature it goes from solid to liquid (tensile=pull, compressive=pull).
Strength - How well it resists a force.
Stiffness - How much it doesn't bend.
Hardness - How hard it is to cut.
Density - Mass/unit volume. - 2Name some uses for materials based on their properties.Plastics - Some hard, strong and stiff. Some low density. Some mouldable. (TV cases, computers)
Rubber - Strong but soft and flexible. Mouldable. (car tyres)
Nylon Fibres - Soft and flexible. Strong, tensile. (ropes, clothing fabric) - 3What is crude oil and how is it formed?Crude oil is a mixture of hydrocarbons (chains of carbon and hydrogen of various lengths).
It is formed from dead plants and animals buried underground under high pressure and heat for millions of years. - 4What causes hydrocarbon properties to be different and how?Chain length -
longer = higher boiling point and more viscous.
Shorter= Lower boiling point and more thin (some are gasses) - 5What bonds are there in crude oil?Strong covalent bonds between carbons and hydrogens with each molecule
Intermolecular forces of attraction between different hydrocarbon molecules in the crude oil - 6Why do larger hydrocarbons have higher boiling points?Larger chains means more intermolecular bonds meaning more energy is needed to break them therefore meaning that they have a higher boiling point.
- 7How is crude oil separated?Fractional distillation.
- 8Explain fractional distillation.Fractional distillation is the separating of different molecules of hydrocarbons into different group depending on their sizes. The larger molecules with higher boiling point stay at the bottom fraction and molecules with the lowest boiling points rise to the top.
- 9Name some uses of each hydrocarbons.SMALLEST-Refinery gas
Petrol
Naphtha
Kerosene (jet fuel)
Diesel
Lubricating oil
LARGEST-Bitumen(used for road surface) - 10Define polymerisation.The chemical bonding of monomers to form longer molecules (polymers) through reactions.
- 11Why can only alkenes (not alkanes) be made into polymers?They have a double bond meaning that the monomers can be joined (making polymers).
- 12How can polymers be modified to give them different properties?Cross links
Crystallisation
Chain length
Plasticisers - 13What are cross links and how do they affect properties of a polymer?Chemical bonds between the polymer chains which create intramolecular bonds which need more energy than intermolecular bond.
Makes stiffer, stronger and more heat resistant. - 14What is crystallinity and how does it affect properties of a polymer?If a polymer is more crystalline it means the chains are straighter meaning the chains are closer, increasing the strength of the intermolecular bonds meaning more energy is needed to break them.
Makes higher density, stronger and higher melting point. - 15What is chain length and how does it affect properties of a polymer?Chain length is how long the polymer chains are. If the chains are longer then there are more intermolecular bonds meaning more energy is needed to break them.
Makes stiff and higher melting points. - 16What are plasticisers and how do they affect properties of a polymer?Plasticisers can be added to polymers and work by getting in between the polymer chains and reducing the forces between them.
Make soft. - 17Define nanotechnology.Technology using particles from 1-100 nanometers (NM) across.
- 18How big is a nanometer?-9
1x10 m - 19Name: 1 accidentally formed nanoparticle 1 naturally formed nanoparticleCombustion - When fuels are burnt, nanoscale soot particles are produced
Sea spray - Nanoscale salt particles which are present in the atmosphere - 20Name some uses of nanoparticles.Silver nanoparticles are added to polymer fibres giving them antibacterial properties (e.g in socks).
Nanoparticles are added to plastics in sports equipment to make it stronger and more lightweight.
Nanoparticles are also added to suncream. - 21Why are nanoparticles effective?They have a high surface area to volume ratio.
- 22What are the issues with nanoparticles? Give examples if possible.- The way they affect the body isn't fully understood and hasn't been tested enough.
E.G WHEN WASHED SILVER NANOPARTICLES COULD ENTER WATER SUPPLY AND THEN BE CONSUMED
- One solution is to clearly label products with nanoparticles in.
Información
- Descripción
- GCSE (C2) Science Fichas sobre C2, creado por Nik Lerche el 18/11/2015.
- Creado por
- Nik Lerche
- Visitas
- 0
- Valoración