Factors Affecting the Decomposition of Marble Buildings by Acid Rain :: GCSE Chemistry Coursework Investigation

Factors Affecting the Decomposition of Marble Buildings by Acid Rain Background Acid Rain: Nitrogen acids and sulphur dioxides come out of tall chimneys and vehicles. These go into the air, and air currents carry the gases away, and they react with water vapour and oxygen. This produces H2SO4 (sulphuric acid) and HNO3 (nitric acid). The acids become part of a cloud, and it falls down to earth, as acid rain or snow. This can end up miles away from the original source. The acid rain removes nutrients from soil, so plants can not get to them, so this eventually kills surrounding die. It can also get into lakes and rivers, which can kill fish. The same is true for acid snow as it kills fish in rivers and lakes. Rates of reactions: This is how quick a reaction is, you can find out the rate of a reaction by seeing how much of it is used up in a particular amount of time. You could also measure how much is produced as a result of the reaction in a particular amount of time. Reactions take place because of collisions, the particles (can be atoms, ions or molecules) collide, and a reaction occurs between particles. If there are more collisions, the reaction will be much quicker. But it also depends on whether the collision has enough energy, to be successful. If there is not enough energy, then the collision will be unsuccessful, but if there is, it will be successful, and a reaction will occur. Unsuccessful collisions take place when the activation energy is not reached. The activation energy is the amount of energy needed for a successful collision. There are factors which affect the rate of a reaction, and also if the collisions are successful or not. Temperature rise gives particles more energy, and as thy move around more and much quicker they have collisions. Also it gives particles more energy, so that when they collide the collisions are more successful. Both these things mean that there is a faster reaction rate. But, if temperature decreases there is a slower reaction rate, as there is less energy. If there is larger surface area, it also means that reactions are quicker. The reason for this is that there are more particles exposed to take part in collisions. So the more collisions means, more successful collisions, and a faster reaction rate. If surface area is decreased, then there are fewer exposed particles, therefore a slower reaction rate. Also concentration, affects reaction rate. In gases it is the pressure. If there is a greater concentration, then there are more particles in the same volume.