The Effects of Acid Rain on Statues :: Acid Rain Chemical Reactions Essays

The Effects of Acid Rain on Statues Introduction ------------ During this investigation, I will use dilute hydrochloric acid as the acid rain and crushed calcium carbonate as the chemical of the statues. Then I will time how long it takes for the limestone powder to react until there is no more left when the acid is added to it. Rain contains acid naturally as it collects carbon dioxide from the air and makes carbonic acid. Rain normally has a pH of about 5.5 – it is slightly acidic due to the carbon dioxide dissolved in it. It is a stronger acid if gases like sulphur dioxide and nitrogen oxides escape into the air from the burning fossil fuels, because they are dissolved by the rain and produce sulphuric and nitric acids that does more damage in a faster time. Acid rain reacts with statues and buildings that contain calcium carbonate and form carbon dioxide and water. The dilute hydrochloric acid in this investigation will have the same effect on the limestone as the acid rain on the statues. Yet, the only difference is that in nature, the acid rain reacted with the statue as a whole body, which takes approximately hundred years to corrode the object, whereas the hydrochloric acid in this investigation will take only few seconds to react with the limestone powder. Planning Aim --- The aim of my experiment is to investigate if the speed at which the limestones are dissolved is changed by how concentrated the acid is. Equipment To do my experiment, I will need beakers, a paper spoon, a stop clock, limestone powders, stirring rod, measuring cylinders and an electronic balance for powders Plan For this experiment, I will use 30mls of the acid each time and 1gm of powdered calcium carbonate. The concentration of the acid will be changed by adding water and less acid each time. First, I will use a paper spoon to spoon out the limestone powder and weigh it on the electronic balance. Next, take out the excess powder until the weight is 1gm. Then use two measuring cylinders, with each measuring the amount of water and dilute hydrochloric acid that should be added, e.g. when there is 30mls of acid, 0mls of water will be added; when there is 25mls of acid, 5mls of water will be added, and so on. The total amount will always be 30mls. Afterwards, I will pour the powder into a beaker that contain correct amount of acid in it and use a stop clock to time how long it will take for the powder to disappear. A stirring rod will be used so that no lumps would form.