- Report Table Fp 1 Freezing Point Of Solvent Stearic Acid Time And Temperature Data For The Freezing Point Of Stearic 1 (24.75 KiB) Viewed 56 times
- Report Table Fp 1 Freezing Point Of Solvent Stearic Acid Time And Temperature Data For The Freezing Point Of Stearic 2 (34.74 KiB) Viewed 56 times
- Report Table Fp 1 Freezing Point Of Solvent Stearic Acid Time And Temperature Data For The Freezing Point Of Stearic 3 (29.79 KiB) Viewed 56 times
- Report Table Fp 1 Freezing Point Of Solvent Stearic Acid Time And Temperature Data For The Freezing Point Of Stearic 4 (49.28 KiB) Viewed 56 times
780 692 810 69.2 840 69.2 870 69.2 900 692 Time and Temperature Data: Cooling Curves for Solution with Unknown From the procedure 11. Obtain an unknown compound and record its number on your data sheet 12. Weigh out approximately 1 gram to the nearest 0.01 g and record the mass on your data sheet. Unknown number 3 Weight of unknown used 1.0181 From the procedure 13. Add the unknown compound to the test tube containing the stearic acid. 14. Place the mixture in the hot water bath and heat it until its temperature reaches 85 °C 15. Stir the molten mixture and repeat the above procedure used for pure stearic acid for the solution of the unknown and stearic acid. Report Table FP.2: Freezing Point of Solution Time and temperature data for the freezing point of unkown solute 2nd Cooling Curve Temperature (°C) Time (Seconds) 0 85B 30 84.4 60 83.0 90 81.7 120 80.3 150 79.0 180 77.7 210 76.5 חזר
210 76.5 240 753 270 741 300 730 330 71.9 360 70.9 390 69.9 420 69.0 450 682 480 67.4 510 668 540 66.3 570 66.1 600 66.0 630 65.9 660 659 690 65.9 720 65.9 750 659 780 658 810 658 840 65.8 870 658 900 658 (34pts) Determination of Freezing Points Use the data tables shown above to make two plots of cooling curves using a graphing program, like Excel. Each cooling curve is a plot of temperature (y-axis) versus time (x-axis), and contains a cooling porting (when the liquid is cooling) and a freezing portion (when the liquid is turning to solid). You will need to generate a trendline for each portion of the cooling curve. In order to do this, you will need to identify which points to include in the cooling portion of the curve and which points to include in the freezing portion of the curve. For each cooling curve, you will need to
(34pts) Determination of Freezing Points Use the data tables shown above to make two plots of cooling curves using a graphing program, like Excel. Each cooling curve is a plot of temperature (y-axis) versus time (x-axis), and contains a cooling porting (when the liquid is cooling) and a freezing portion (when the liquid is turning to solid). You will need to generate a trendline for each portion of the cooling curve. In order to do this, you will need to identify which points to include in the cooling portion of the curve and which points to include in the freezing portion of the curve. For each cooling curve, you will need to identify three points • the last temperature measurement to include in the cooling portion of the curve • the first time to include in the freezing portion of the curves • the last time to include in the freezing portion of the curves Then, generate a trendline for each portion of the curves and record their slopes and y intercepts in the table below. Report Table FP.3: Freezing Point Determination Table view List view Calculations for the cooling curve of stearic acid and the unknown solution Cooling Curve #1 Cooling Curve #2 Choose Choose Final time to include in cooling portion 570 seconds 600 seconds -5.36 -5.05 Slope of cooling portion y-Intercept of cooling portion 69.7 66.2 First time to include in freezing portion Choose Choose... Choose Choose... Choose Final time to include in freezing portion Choose.. Choose Choose... Slope of freezing portion y-Intercept of freezing portion Time at which 2 lines intersect (seconds) Calculated freezing point ("C)