The greater the activation energy the higher the ignition energy is. This will increase the chance of complete combustion occurring Sulfur dioxide is produced from impurities in the some fuels most commonly coals. Removing sulphur from coal is difficult, so power stations try to use low-sulfur coals whenever possible.
Provides a surface on which reaction occurs more rapidly that it does in the bulk of the reaction mixture. Explain the role of catalysts in changing the activation energy and hence the rate of chemical reaction Catalysts are particularly useful when the uncatalysed reaction has very high activation energy and is therefore slow.
This gas can cause breathing difficulties at quite low concentrations. The nickel is heterogenous catalyst. Homogenous reactions occur when the reactants in are in the same state. Alternatively sulphur dioxide has to be removed from the effluent gas at power stations but this is expensive.
Identify the sources of pollution which accompany the combustion of organic compounds and explain how these can be avoided If insufficient air is available for the complete combustion of a fuel i.
The way to minimise production of carbon monoxide and soot is to use excess air that is to keep the air to fuel ratio high. Also fuel exhaust are sometime coated with platinum and rhodium which provides a surface to remove nitric oxide, carbon monoxide and unburnt hydrocarbons.
The ignition temperature of a fuel-air mixture is the minimum temperature to which the mixture or portion of it must be heated in order for combustion to occur.
Homogenous catalysts are usually a substance e. Work through the bulk of the reaction mixture. An explosion is just an extremely rapid reaction few microseconds Explain the importance of collisions between reacting particles as a criterion for determining reaction rates Anything that increases the rate of reaction at which collisions occur will increase the rate of reaction.
Speed is limited by the amount of air that can access the solid i.
Activation energy shows the energy change from ignition to the reactants beginning to form products. Factors which affect the reaction rate in these reactions are: Stirring increases the rate of collision between reactant particles and so increases the rate of reaction Explain the relationship between temperature and the kinetic energy of particles As temperature increases, the average kinetic energy and so the speed of particles increase.
The catalyst usually provides a pathway of a lower activation energy shows below.
Steam train or fire place. A measure of the ease of ignition is the ignition temperature.
Explain the relationship between ignition temperature and activation energy Some fuels are easier to set fire to than others. Factors that affect the reaction rate are the same as homogenous with the additions of:Oct 30, · -Describe Combustion in terms of slow, spontaneus and explosive reactions and explain the condition under which these occue This is relatively self-explantory, but I can't think of any immediate examples of each.
describe combustion in terms of slow, spontaneous and explosive reactions and explain the conditions under which these occur. explain the importance of collisions between reacting particles as a criterion for determining reaction rates.
Mar 16, · Explosive combustion occurs when gases expand at a rapid rate. An explosive combustion is caused by a chemical reaction involving a fuel and oxidizer.
The energy released during this chemical reaction is in the form of heat and a pressure wave. The 5/5. Describe combustion in terms of slow, spontaneous and explosive reactions and explain the conditions under which these occur Combustion reactions are spontaneous, this means that once started they proceed without further assistance and continue until all the fuel is used up.
Jun 06, · Describe combustion reactions in terms of slow, spontaneous and explosive reactions, give examples? Bush explains slow reaction to September 11 attacks? Under what conditions do slow, spontaneous and explosive reactions occur?Status: Resolved.
Describe combustion in terms of slow, spontaneous and explosive reactions and explain the conditions under which these occur Combustion is a chemical reaction because:5/5(2).Download