Experiment 15 Variation of Solubility with Temperature and Solvent Chemistry 1220 September 8th 2013 Raffeal Bennett Purpose The purpose of this experiment was to utilize laboratory techniques to see if temperature and solute solvent affect solubility Solubility was also compared by using different units and quantified by utilizing different graphic techniques to study trends Procedure Refer to pages 20 22 of General Chemistry 1220 Laboratory Manual by Hayden McNeil Publishing Department of Chemistry at The Ohio State University 2013 2014 Calculations Please see attached calculations Graphs Please see attached graphs Discussion In this experiment the solubility of potassium dichromate in water was found to increase as temperature increased Moreover the solubility of potassium dichromate in 70 30 water dioxane was also found to increase as temperature increased Each graph shows concentration and mole fraction respectively and represents this trend with a positive sloped curve Generally the solubility of an ionic solute in water increases with increasing temperature The reason that this is not a linear relationship and instead a curved one is because the solubility being affected by the temperature is in terms of competing energies Solubility depends on temperature solute solvent interactions gas and pressure Furthermore the solute solvent attractions must be strong enough to compete with solute solute and solvent solvent attractions The reason that the sample was able to dissolve in the solvent is because likes dissolve likes The potassium dichromate was able to dissolve in both the water and the 30 70 water dioxane but only with the addition of heat which is the addition of energy an endothermic process The graphs represent the data well however the points do not create a perfectly smooth curve due to inconsistencies and possible errors Error in the experiment could have been not observing the exact temperature when the crystals began to crystalize Also another source of error could have been not putting the solubility apparatus in the water bath fast enough to produce crystals Conclusion In part A and B the solubility of potassium dichromate in water as a function of temperature was found by heating the solution until the sample was completely dissolved However Part B just used less sample In part C the solute potassium dichromate was dissolved in a different solvent water dioxane Results demonstrated that as temperature increases the solubility also increases In closing there are many things that affect solubility and in this lab it was concluded that temperature affects it greatly