Dissolution and precipitation reactions are very important chemical reactions because it is applied to many aspects of the industries in medicine, food, water etc. The objectives of this laboratory experiment is to become familiar with dissolution and precipitation equilibria, develop a lab technique suitable for the determination of the solubility for a sparingly soluble salt, Ba(NO3)2 (s) at room temperature and measure the common ion effect in solubility of Ba(NO3)2 (s) in an acidic solution, HNO3 (aq). Procedure:
In this lab, the evaporation technique was used to determine the solubility of the salt at room temperature in water. First a 250ml beaker was weighed and the mass was recorded. Then 5.0g of barium nitrate was weighed into the beaker. Next, 50ml of distilled water was added to the beaker with the barium nitrate sample. The sample was mixed for ten minutes using the magnetic stirrer. Afterwards, as much as possible of the barium nitrate solution was decanted without losing the solid barium nitrate. To get rid of the excess water, the beaker placed onto a hot plate to evaporate the remaining water I the beaker. One the sample was dry, the mass of the beaker with the dry barium nitrate was weighed, and the mass of the barium nitrate dissolved was calculated. This procedure was repeated for the barium nitrate in acidic solution, HNO3(aq). All data was recorded and the mass of barium nitrated dissolved in acid was calculated.
From the evaporation technique, 4.39g of barium nitrate dissolved in water and 2.34g of barium nitrate dissolved in the acid. From that the concentration of barium nitrate in its saturated solution in water was 0.336mol/L and 0.179mol/L in HNO3. The concentration of Ba2+(aq) ions in saturated solution is the same as the concentration of the saturated barium nitrate solution by dissociation of barium...