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Description
Flashcards by mouldybiscuit, updated more than 1 year ago
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Created by mouldybiscuit
over 9 years ago
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| Question | Answer |
| Define: Crude oil | Dark, smelly liquid. Mixture of hydrocarbons |
| Define: Fractions | Substances with similar boiling points. |
| What does Distillation do? | Separate liquids with different boiling points. |
| Define: Hydrocarbons | Compounds containing only hydrogen and carbon atoms. |
| What is the general formula for alkane molecules? | |
| Define: Saturated Hydrocarbons | Alkanes hydrocarbons that contain as many hydrogen atoms as possible in each molecule. No more hydrogen atoms can be added. |
| Which type of hydrocarbons tend to be more useful? | Short chain hydrocarbons |
| Why are short-chain hydrocarbons more useful? | They are flammable and burn well. |
| Define: Boiling point | The temperature at which a liquid boils or gas condenses. |
| Define: Volatility | The tendency for a substance to turn into gas. |
| Define: Viscosity | How easily a substance flows. |
| Define: Flammability | How easily a substance burns |
| Finish the sentence: The longer the chain of the molecule... | the higher the boiling point. the less volatile it is. the more viscos it is. the less flammable it is. |
| Finish the sentence: The shorter the chain of the molecule... | the lower the boiling point. the more volatile it is. the less viscos it is. the more flammable it is. |
| Define: Fractional Distillation | The process by which we separate out crude oil into hydrocarbons with similar boiling points (called fractions). |
| What is the process of fractional distillation? | 1. Crude oil is vaporised. 2. It is fed at the bottom of the chamber. 3. It is hot at the bottom and cooler as you go up. 4. Gases condense when they reach their boiling points. |
| What happens when you burn a hydrocarbon/ alkane in air? Give an equation. | The hydrocarbon is oxidised (adding oxygen) completely. hydrocarbon + oxygen -> carbon dioxide + water |
| What are the pollutants from burning fuels? | Carbon dioxide (product). Sulphur dioxide (impurity in fuel). Nitrogen oxides (nitrogen reacts with oxygen inside the engine due to high temperatures). Carbon monoxide (incomplete combustion). Particulates (diesel or large molecules do not burn completely). |
| Why is sulphur dioxide a problem? | It is poisonous. It is acidic. It causes acid rain. It causes engine corrosion. |
| Why is carbon monoxide a problem? | It is poisonous. Red blood cells carry it instead of oxygen. |
| Why are nitrogen oxides a problem? | They are poisonous. They trigger asthma attacks. They cause acid rain. |
| Why are particulates a problem? | They get carried into the air. They damage lung cells. They cause cancer. They cause Global Dimming. |
| Why is carbon dioxide a problem? | Greenhouse gas Global Warming |
| Why is Global Warming a problem? | Causing international temperatures to rise. |
| Why is Global Dimming a problem? | Reflecting sunlight back into space. Less sunlight on Earth. Plants: How will they photosynthesize? |
| Why is acid rain a problem? | Damages plants Damages buildings Harms marine life/ fish Can cause skin problems on humans |
| Define: Catalytic converters | Fitted to exhaust systems. Expensive because they contain precious metal catalysts. They have a large surface area so carbon monoxides and nitrogen oxides can react together. |
| What can be used to remove particulates? | Filters in modern diesel engines. They need to burn off trapped solid particles otherwise they get blocked. |
| What is used to remove sulphur dioxide from waste in power stations? | Flue gas desulphurisation. It is reacted with calcium oxide or calcium hydroxide. It is removed from oil and natural gas before it is burnt. |
| What is done to petrol and diesel to reduce sulphur dioxide emissions? | The sulphur impurities are removed before the fuel is burnt. |
| Define: Biofuels | Fuels made from plant or animal products. |
| Define: Biodiesel | A fuel made from vegetable oils for use in diesel engines. |
| Define: Biogas | Gas that can be burnt and is from animal and plant waste. |
| Define: Ethanol | Can be a biofuel if obtained through fermentation of sugar. |
| What are the advantages of using biodiesel? | 1. Less harmful to animals and plants if spilt. 2. Burns more cleanly (less particulates and sulphur dioxide). 3. It will become cheaper to use as crude oil runs out. 4. Carbon neutral. 5. Process also makes other useful products (makes solid waste material to feed to cattle and glycerine which is used to make soap). |
| What are the disadvantages of biodiesel? | 1. Large areas of farmland used. food prices? famine? forests have to be cleared? 2. Not exactly carbon neutral (transporting oil) 3. Destruction of habitats 4. Low temperatures: Biodiesel freezes, turns to sludge. 5. High temperatures: Biodiesel becomes sticky and molecules join together. It clogs engines. |
| What are the advantages of using Hydrogen ( as a biofuel) | It burns cleanly water is the only product water is widely accessible |
| What are the disadvantages of using Hydrogen ( as a biofuel) | 1. Hydrogen has to be obtained through electrolysis of water. (expensive and energy consuming). 2. Explosive so more dangerous. 3. Gas so it takes more space. (storage?). 4. high-pressure cylinders are expensive and dangerous in crashes. |
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