29593405
Description
Flashcards by Malachy Moran-Tun, updated more than 1 year ago
|
|
Created by Malachy Moran-Tun
over 3 years ago
|
|
| Question | Answer |
| How were Natural Gas and Crude Oil Formed? | > Ancient remains of plants and animals > Millions of years, gradually turned into natural gas and crude oil > Not being made anymore (or extremely slowly) |
| What is Fracking? | > Hydraulic fracturing > Way to obtain natural gas and/or other fossil fuels > Water, sand and other substances injected into underground rock |
| What is a Hydrocarbon? | A molecule that contains Carbon and Hydrogen ONLY |
| What is a Finite Resource? | A resource that is NOT made anymore (or made extremely slowly i.e. over millions of years) |
| What is a Non-Renewable Resource? | A resource that is being used faster than it is being made |
| What is Crude Oil? | > Main source of hydrocarbons > Complex mixture of many different hydrocarbons (mostly alkanes) |
| How can Crude Oil be Separated? | > Fractional distillation > Oil heated until most of it has turned into gas > Gas enters a fractionating column > Column has a temperature gradient (i.e. hot at the bottom, cool at the top) > The longer hydrocarbons have higher boiling points so they drain out early on > Shorter hydrocarbons have lower boiling points so they drain out near the top |
| What are the Main Fractions in Crude Oil (from Shortest to Longest)? | > Gases > Petrol > Kerosene > Diesel Oil > Fuel Oil > Bitumen |
| What are the uses for each (main) Fraction of Crude Oil? | > Gases - domestic heating and cooking > Petrol - fuel for cars > Kerosene - fuel for aircrafts > Diesel Oil - fuel for cars and trains > Fuel Oil - fuel for large ships and power stations > Bitumen - surfacing roads and roofs |
| What is a Homologous Series? | A family of molecules which have the same general formula and share chemical properties |
| What is the General Formula for Alkanes? | CₙH₂ₙ₊₂ |
| What are the first 6 Alkanes and their Formulæ? | Methane - CH₄ Ethane - C₂H₆ Propane - C₃H₈ Butane - C₄H₁₀ Methylbutane* - C₅H₁₂ Cyclohexane - C₆H₁₂ *aka pentane |
| Why are the Physical Properties Different in Alkanes / Hydrocarbons? | The intermolecular forces are stronger between bigger molecules, which hold the chains of atoms together |
| Why do Longer Hydrocarbons have Higher Boiling Points? | > Intermolecular forces break easier in SMALLER molecules > There is still another place where the force is strong enough to hold in in place > Bonds are harder to break so boiling point is higher |
| Why are Shorter Hydrocarbons Easier to Ignite? | > Shorter hydrocarbons have lower boiling points > The gas molecules mix with oxygen in the air to produce a combustible gas mixture > If the mixture comes in contact with a spark, it will ignite |
| Why are Longer Hydrocarbons more Viscous? | > Viscosity is how easily a substance flows > Stronger force between hydrocarbon molecules > Harder for the liquid to flow - higher viscosity |
| What is Complete Combustion? | Combustion with enough oxygen so only CO₂ and H₂O are produced |
| What is Incomplete Combustion and why is it Dangerous? | > Combustion with limited oxygen > Less oxygen than CO₂ > Produces Carbon Monoxide - CO (toxic gas) > Forms soot (Carbon) > CO can stop blood from carrying oxygen round the body > Soot can cause respiratory problems |
| What's the Difference between Alkanes and Alkenes? | Alkanes - Saturated, they have all single bonds Alkenes - Unsaturated, they have a double bond |
| What is Cracking? | Chemical reaction in which large alkane molecules are split into smaller alkanes and alkenes |
| Why is Cracking Used? | To match supply and demand of hydrocarbons from crude oil - some has a greater demand than what appears in crude oil (also can help make polymers / plastics) |
| What can Sulfur (SO₂) Dioxide cause? | Acid rain (pH below 5.2) since the sulfur dioxide mixes with the clouds to form (dilute) sulfuric acid |
| What are some problems with Acid Rain? | > Damages plants > Issues in ocean wildlife - fish death and coral damage > Damages limestone > Damages marble stonework > Can make metal corrode |
| What are Nitrogen Oxides produced from? | Reactions between nitrogen (N₂) and Oxygen (O₂) in the air, released by combustion reactions (for example, in cars) |
| Why are Nitrogen Oxides Harmful? | They can contribute to acid rain and cause photochemical smog, which is air pollution that can cause breathing problems, headaches, and tiredness |
| What are the Advantages of using Hydrogen as Fuel? | > Very clean > Only waste product is water > No pollutants like CO₂, CO or soot > Obtained from water, which is a renewable resource > The product of water can be reused |
| What are the Disadvantages of using Hydrogen as Fuel? | > Requires a special and expensive engine > H₂ needs to be manufacture, which is expensive and usually requires energy from external sources > H₂ is hard to store |
Want to create your own Flashcards for free with GoConqr? Learn more.