Solubility Equilibrium and the Effect of Temperature Essays

AP Chemistry Background The solubility product constant, Ksp, is a particular type of equilibrium constant. The equilibrium is formed when an ionic solid dissolves in water to form a saturated solution. The equilibrium exists between the aqueous ions and the undissolved solid. A saturated solution contains the maximum concentration of ions of the substance that can dissolve at the solutions temperature. A knowledge of the Ksp of a salt is useful, since it allows us to determine the concentration of ions of the compound in a saturated solution. This allows us to control a solution so that precipitation of a compound will not occur, or to find the concentration needed to cause a precipitate to form. The solubility product which will be

At five minute intervals over the next fifteen minute period, record the color intensity of the solution of each test tube.

4. We observed the test tubes and compared the colors produced from the reaction to the color palette in 1 minute intervals for 5 minutes total.

· I set up the apparatus as shown in the diagram. I then placed a

Add 4 drops of phenolphthalein in to the prepared acetic acid, and check whether the color changes to dark pink.

Based on the data, solubility of Potassium Nitrate and temperature are directly proportional. This is indicated in the results of the experiment because as the amount of solute in the solution increases, the solubility of the solution increases. As the solubility increases, the temperature also increases, meaning that the relationship is directly proportional.

Temperature is known as one of the factors that affect the solubility of a gas in its solvent. Because the enthalpy of solution for gases dissolved in waters is usually

Remove the tubes and add 2-3 drops of Iodine – potassium – iodide solution to each tube.

The null hypothesis will be that the test tubes with an increase in temperature, pH values, enzyme concentrations, and substrate concentration will have a very small color change or no color change at all. The alternate hypothesis is that the test tubes containing an increase in temperature, pH values, enzyme concentrations, and substrate concentration will all have an intense color change; the more the change, the more intense the color change will be.

As the temperature of water increases, the particles of solid Potassium chloride, KCl, which are absorbing energy from its surrounding, start moving more easily between the solution and its solid state because. According to the second law of thermodynamics, the particles will shift to the more disordered, more highly dispersed solution state. I predict that as the temperature of a KCl and water mixture increases, then the solubility of the KCl will also increase.

Half of each tube’s contents are poured into a new test tube each respectively after the tubes are incubated for 1 hour. One set of tubes is tested for:

During the Benedict's test, the contents of tube B did not change, indicating the absence of sugar in that particular substance. However, the contents of tube A did change orange indicating the presence of sugar in that substance. During the Lugol's test, the content of tube A did not change dark purple indicating the absence of starch in that substance However, the content of tube B changed to dark purple

Also, some fruits especially beetroot made it very difficult to read the colour coding as the juice stained the reactant square. To further improve this validity issue I suggest getting accustomed to the different colour-codings beforehand, that way you will know straight away which colour is which without doubt and I would avoid using any food that have the ability to stain paper. The experiment, although it went relatively smooth had lots of variables that were uncontrollable which made the experiment less

Solute – A solute is the material (solid, liquid or gas) that is dissolved in the solvent to create the solution.

Next two Dissolved Oxygen TesTab where dropped into the test tube. After that screw the cap on the tube, make check to make sure there are no air bubbles present. Next invert the tube for a time limit of 4 minutes until the tablets and disintegrated. After a five minute time period as elapsed a color should start to develop, compare the color sample to the dissolved oxygen color chart and record the data. After the dissolved oxygen data was recorded, the group tested the Wall pond for Nitrate. First, fill the square-sided test tube with 5mL of the water sample. Next add one Nitrate WR CRA TesTab. Next, put the cap on the test tube and invert until the tablets have disintegrated. After the five-minute time-period has passed, wait for the red color to develop, compare the color of the sample to the Nitrate color chart, and record the results as ppm Nitrate. Next the group studied the wall pond for Phosphate. First fill the tall square-sided with 10mL of the water sample. Next, add one Phosphorus TesTab. Next, screw the cap on the test-tub and invert until the tablet has disintegrated, and after five minutes a blue color should start to develop. Lastly, compare the color to the sample to the Phosphate color chart and record the results has ppm Phosphate. Next the wall pond was tested for pH. First fill the square-sided test tube with 10mL of the water sample. Next add one pH tablet. Then screw the cap on the test tube and invert until the