Diseño Lluvia Acida

Lab Report
Title: The effects of acid rain on the concentration of aluminum cations in lakes
Aim: How will the solubility of aluminum in soil change with pH
Introduction: Rain is considered tobe acid when its pH value is lower than 5.2. This pH will determine the amount of aluminum cations that will dissolve in water. With four acidic pHs (1, 2, 3 and 4) it is going to be observed how thealuminum dissolved in water will vary, this is going to be measured with a colorimeter. As the aluminum is colorless, it will react with some compounds so that it can be measured by the apparatusVariables: Independent: pH of solution added to water
Dependent: concentration of aluminum cations
Controlled: time, type of soil, water used, temperature, amount of soil, components of soil
Materials:water, H2SO4 (acid found in rain), flasks/beakers/test tubes, colorimeter, KOH
Procedure: Place 5 fish tanks in a room with a temperature of 20°C
The aluminum cations get to the water through thesoil so place a certain amount of soil in each fish tank. Making sure all the soil comes from the same place and that each tank contains the same amount.
Fill them with distilled water.
Label theeach tank with the numbers 1, 2, 3, 4, 0. This will represent the pH in each case, the “1” will be pH=1, the “4” will be pH=4 and the control will be “0” and it will have only distilled water, no acid,hence its pH=7. Rain is considered to be acid when the pH is lower than 5.2, so this is why the pHs used are all lower then this value, except for the control one
In the tank labeled “1” pour someH2SO4 0.79 mol dm3, In the tank labeled “2” pour some H2SO4 7.9x10-3 mol dm3, In the tank labeled “3” pour some H2SO4 7.9x10-5 mol dm3 and In the tank labeled “4” pour some H2SO4 7.9x10-7 mol dm3.After one day, when the aluminum concentration will not increase any more take samples from each tank and use a colorimeter to measure the aluminum concentration. The steps to measure it are; add KOH...