Varying Salt Concentration on Plant Growth Experiment

1. Slow combustion take place in gas stove. Slow combustion will occur when there is not enough oxygen to allow the fuel to react completely to produce carbon dioxide and water. The slow combustion will have small surface area which reduces the reaction. Spontaneous combustion is a mass of material when bursting into flame as a result of chemical reactions within the substance, without the addition of heat from an external source. Examples of spontaneous finely powdered ores, coal, straw Explosive combustion occurs in cylinders of petrol and diesel engines in vehicles or bombs. An explosion is just an extremely rapid reaction.

2. The increase rate of reaction at which collisions occur will increase the rate of reaction. Temperature also increases as the kinetic energy increases, the number of collisions increases, as a result the reaction rate increasing. Factors which affect the reaction rate in these reactions are concentration; increasing concentrations leads to increased reaction as there is more chance of atoms colliding. Homogeneous reactions occur when the reactants in are in the same state. Heterogeneous reactions occur between reactants that are in different states. Factors that affect the reaction rate are the same as homogeneous with the addition of surface area to volume ratio: breaking up solid increases the surface area which increases the amount of collision, therefore reaction rate increases. And stirring: stirring keeps the solid suspended in the solution so that the solid's maximum surface area is exposed. Stirring increases the rate of collision between reactant particles and so increases the rate of reaction.

3. There is a risk of explosion when several elements are present of oxygen in air, for example a fuel: either gas or vapors. A source of combustion: hot spot flame or spark. The concentration of dust is very high. The environment then is dangerous: a rise in temperature, or even a spark, can trigger an explosion. The more surface area on which collisions can occur, the faster the reaction. You can hold a burning match to a large chunk of coal and nothing will happen. But if you take that same piece of coal, grind it up very, very fine, throw it up into the air, and strike a match, you'll get an explosion because of the increased surface area of the coal.

4. Safety measures to prevent explosions include storage, remove any ignition sources, limiting the effects of explosions to minimize injuries, transport the location. Explosive reactions, which occur as a result of rapid combustion, produce large quantities of heat energy, causing nearby gases to expand rapidly. Explosions are most likely to occur with fuels that vaporise readily, producing a fuel vapour. Stored and transported in such a way that vapours cannot build up to form an explosive fuel vapour/air mixture. First steps would be to contain combustible dust to areas that are properly designed and located,