Carbonyl compounds Flashcards
Chemical formula for combustion of hydrocarbons (provide example)
Hydrocarbon( methane) + oxygen → carbon dioxide + water
(CH4 + 2O2 → CO2 + 2H2O)
What are the advantages of hydrogen as a fuel
It is a renewable resource as it is made from electrolysis of water.
It does not contribute to global warming as it does not release carbon dioxide.
What are the disadvantages of hydrogen as a fuelm
Large amounts of electricity are required to produce it from electrolysis of water (and most electricity is still produced by burning fossil fuels).
Bulky and heavy storage containers are required to contain the gas.
It forms a flammable and potentially explosive mixture with air.
What is the fire triangle method to prevent and extinguish fires
1)
The main method used to remove heat is to put water on the fire. This method is suitable for most fires where the fuel is solid (e.g. paper, wood, coal, etc).
2)
Methods for removing oxygen include:
CO2 extinguishers, foam extinguishers,fire blankets.
Most suitable for fires that water is not suitable for such as electrical fires and liquid fuel fires (e.g. chip pan fires and aircraft fuel fires).
3)
It is difficult to remove the fuel during a fire, so the removal of fuel is mostly used in fire prevention.
Examples include:
managed forests having sections with no trees to prevent forest fires from spreading – this is known as a firebreak
felling and removing trees around a fire (if there is time) to create a firebreak and stop the fire from spreading.
use of non-flammable or fire-resistant materials in the manufacture of everyday items such as: clothing ,furniture the walls, ceilings and doors of buildings.
How to calculate the energy released per gram of fuel burned.
1)Place the fuel in a spirit burner.
2) Weigh the spirit burner and fuel.
3) Measure 100cm3 of water into a conical flask.
4) Measure the temperature of the water, ensuring the thermometer does not touch the bottom of the flask.
5) Use the spirit burner to heat the water in the flask for 5 minutes.
6)Measure the temperature of the water to calculate the temperature rise.
7) Weigh the burner and fuel again once it has cooled to calculate the mass of fuel used.
8)Calculate the energy released by the fuel using the following equation:
Energy released( J / g)=
mass of water X 4.2 X temp rise
———————————————
Mass of alcohol burned
9) Calculate the energy released per gram of fuel by dividing the energy released by the mass of fuel used.
Chemical formula for combustion of alcohols (provide example)
ethanol + oxygen → carbon dioxide + water
CH3CH2OH + 3O2 → 2CO2 + 3H2O
Chemical formula for combustion of hydrogen (provide example)
hydrogen + oxygen → water
2H2 + O2 → 2H2O
