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Unformatted text preview: NAME and ID Number: Christina Hong #0862620 LAB PARTNER:Travis Hyunh Quiz Section: AR Total Points = 60 (5 notebook, 55 template) PURPOSE AND METHOD DATA AND CALCULATIONS A. Standardization of NaOH Run 1 Run 2 Run 3** Mass of KHP, g 0.134 g 0.140 g 0.142 g moles KHP 6.56x10^4 6.86x10^4 6.95x10^4 Initial buret reading, mL 0.00 mL 0.00 mL 0.00 mL Final buret reading, mL 7.25 mL 6.80 mL 7.25 mL mL NaOH titrated 7.25mL 6.80mL 7.25mL L NaOH titrated 0.00725L 0.00680L 0.00725L [NaOH], moles/L 9.048x10^2 1.009x101 9.586x10^2 Average, [NaOH] 9.574x10^2 M 3 pts Table 1: NaOH Standardization How are the solubility products (K sp ) of KHP at various temperatures determined? ( 3 pts ) The solubility products (Ksp) of KHP at various temperatures are determined First I take the average [NaOH] from part A of this experiment. Then I calculate the NaOH mL added to the solution. I change mL to L, so I can use this value to determine the mmoles HP of one trial. I know that the ratio of HP and NaOH is the 1:1, the same, so I can say that mmoles NaOH=mmoles HP. Then I use the equation mmoles HP=([NaOH] average X Liters of NaOH added)/(1.0x10^3 moles) to determine the mmoles HP. Next I take the mmoles HP and divide it by the mL of HP used in the titration, which is 1mL, in order to determine the molarity of HP. The equation for this is Molarity HP= mmoles HP/1mL HP added. Finally, since the ratio of HP and NaOH is 1:1, I use the equation Ksp=[HP][NaOH]=[HP]^2 to determine the Ksp of KHP at a certain temperature. How is K sp in a saturated solution of KHP in 0.50 M KCl determined? (3 pts ) First, I calculate the average molarity of HP from the titration of RT KHP in KCl with NaOH(aq) in part C. Then, I multiply the average molarity of HP by the [K+] in original solution, in order to determine the Ksp in a saturated solution of KHP in 0.50 M KCl. There are several steps to calculate the [K+] in original solution. First I calculate the [K+] in measured solution. In order to do so, I have to use the equation formulated from the graph in part C and the intensity found from during the flame photometer part of the experiment in order to calculate "x" (this is the [K+] in measured solution). After calculating the [K+] in measured solution, I use this value and multiply it by the dilution factor, which is 2,500 to determine the [K+] in original solution. Finally, I multiply this [K+] value by the average molarity of HP to get the desired Ksp. EXPERIMENT 4: THERMODYNAMICS II THE TEMPERATURE DEPENDENCE OF THE SOLUBILITY PRODUCT, HEAT OF SOLUTION, AND ENTROPY OF SOLUTION OF POTASSIUM HYDROGEN PHTHALATE Show the calculation for determining [NaOH]for one of the runs. May be typed or NEATLY handwritten....
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 Winter '08
 Chiu
 Chemistry, pH, Solubility, Sodium hydroxide, Solubility equilibrium

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