organic chemistry Flashcards
nonrenewable resources
those that are used faster than they can be replenished.
non-renewable fuels
Coal, oil and natural gas
fuel
a substance with stored energy that can be released relatively easily, for use as heating or power.
how are fossil fuels made?
fossil fuels are made from ancient plants, animals and micro organisms that contain carbon and hydrogen, that are buried under tons of mud, sand and rock thus located in the earth’s crust. These biological material undergo complex changes to become fossil fuels. these can be burned for energy.
how is coal formed?
Coal is formed from ancient plants, animals and micro-organisms that are buried under tons of mud, sand and rock. Once this biological material has undergone complex changes to become fossil fuels for example , coal , oil and natural gas . The organic matter still retains some of the chemical energy of the plants originally accumulated by carrying out photosynthesis . The chemical energy in fossil fuels can be considered as trapped solar energy .
combustion reaction for Coal
C + O2 → co2
fuels from crude oil (petroleum)
petroleum, or crude oil is a mixture of hydrocarbon molecules that are mostly alkanes. Crude oil is no use as a fuel until its components can be separated (by fractional distillation) into petrol, diesel, kerosene, and LPG. LPG is liquified petroleum gas.
how is natural gas made?
Natural gas is another fossil fuel found in deposits in the earths crust. It is drilled out and comes to the surface. The extraction of natural gas from coal or shale deposits usually involves fracking. This process is where the sand, water and other chemicals are injected into the deposit at high-pressure to free the gas from coal or shale. However, fracking can impact the local environment and underwater supplies due to the chemicals that are injected into the deposit. natural gas, is it composed, mainly of methane and small amounts of ethane and propane. Water, sulfur, carbon dioxide and nitrogen might also be present in natural gas.
Complete combustion
where fuels are ignited in excess air (oxygen) and they produce carbon dioxide, water and releases considerable amounts of energy
incomplete combustion
occurs if o2 supply is limited (insufficient) and carbon monoxide and even soot C(s) can be produced
hypoxia
The emission of carbon monoxide from the fuel’s incomplete combustion can cause hypoxia.
the kyoto protocol
an objective of the United Nations Framework Convention on Climate Change (UNFCCC) to reduce the onset of global warming by reducing greenhouse gas emissions.
energy density
The amount of energy stored (in a system) per unit mass e.g. units are usually J/L, J/m^3
What is photochemical smog?
Photochemical smog is a toxic mixture of various chemical pollutants produced when sunlight interacts with car exhaust gases.
catalysts
Certain chemical substances, known as catalysts, have the ability to speed up chemical reactions while they remain chemically unchanged at the end of the reaction.
Which metals are used in a vehicle catalytic converter and what do each of them do?
Its operation relies on the catalytic ability of metals like platinum, palladium and rhodium to rapidly convert toxic and polluting vehicle exhaust gas into harmless nontoxic substances.
