| | | Mass A | Mass B | Mass B - A | | | Liquid | Volume(mL) | GraduatedCylinder (g) | GraduatedCylinderwith liquid (g) | Liquid (g) | Densityg/mL | %Error | Water | 5 | 15.8 | 20.8 | 5 | 1 | 0 | Isopropyl alcohol | 5 | 15.8 | 19.5 | 3.9 | 0.78 | 0.76 | .76 Data Table 5: Magnet – Measurement Method. | Object: | Mass(g) | Length(cm) | Width(cm) | Height(cm) | Volume(cm3) | Density(g/cm3) | Magnet | 4.0 | 2.5 | 0.6 | 0.6 | 0.9 | 0.225 | Data Table 6: Displacement method. | Object | Mass(g) | Initial volume of graduated cylinder (mL) | Final volume of graduated cylinder (mL) | Object Volume (mL) | Density(g/mL) | Magnet | 4.0 | 8 | 10 | 2 | 2
2) Percent recovery for isolation of benzoic acid % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.43/1.01) x100% = 42.57% That concludes that the percent recovery is 42,57%. 3) Percent recovery for isolation of hydroquinone dimethyl ether % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.16/1.01) x100% = 15.84% That concludes that the percent recovery is 15.84%. Table 2: : Experimental IR peaks compared to literature IR peaks for Benzoic acid Functional groups | Experimental peak (cm-1) | Literature peak (cm-1) | O-H | 3407-2563 | 3400-2564 | C=O | 1689 | 1689 | C-H |
Questions and answers What catalyst is used in the reaction? H+ from sulphuric acid H¬2SO4. Which reactant is limiting? m(ethanol)=10×0.789×0.95≈7.4955 g m(acetic acid)=10×1.049×0.99≈10.4 g M(ethanol)=46.026 〖gmol〗^(-1) M(acetic acid)=60.024〖 gmol〗^(-1) n(ethanol)=7.4955/46.026≈0.1628 mol n(acetic acid)=10.4/60.024≈0.17326 n(acetic acid)>n(ethanol) Meaning ethanol is limiting. Calculate the yield?
| 4.0 | 39.2 | 277.15 | Ice Water – 5 min. | .5 | 32.9 | 273.65 | Object | Estimated Mass (g) | Actual Mass (g) | Actual Mass (kg) | Pen | 7 | 8.6 | .0086 | 3 Pennies | 10 | 7.5 | .0075 | 1 Quarter | 8 | 5.8 | .0058 | 2 Quarters, 3 Dimes | 25 | 18.1 | .0181 | 4 Dimes, 5 Pennies | 30 | 22.2 | .0222 | 3 Quarters, 1 Dime, 5 Pennies | 30 | 32.5 | .0325 | Key | 30 | 16.1 | .0161 | Key, 1 Quarter, 4 Pennies | 50 | 32.4 | .0324 | | | Mass A | Mass B | Mass B-A | | | Liquid | Volume (mL) | Graduated Cylinder | Graduated Cylinder w/ liquid (g) | Liquid (g) | Density g/mL | % error | Water | 5 | 17.0 | 22.0 | 5.0 | 1 | 0 | Isopropyl Alcohol | 5 | 17.0 | 21.25 | 4.25 | .85 | 8% | Object: | Mass (g) | Length (cm) | Width (cm) | Height (cm) | Volume (cm3) | Density (g/cm3) | Magnet | 4.3 | 2.5 | .6 | .6 | .9 | 3.87 | Object | Mass (g) | Initial volume of graduated cylinder (mL) | Final volume of graduated cylinder (mL) | Object Volume (mL) | Density (g/mL) | Magnet | 4.3 | 7 | 7.5 | .5 | 8.6 | Metal Bolt | 8.0 | 6.5 | 7.5 | 1.0 | 8.0 | Object | Mass (g) | Mass of Displaced Water (g) | Volume of Displaced Water (mL) | Density (g/mL) | Metal Bolt | 8.0
Data Table #1 Trial Mass of Stopper Hanging Mass Radius T1 T2 T3 Revolutions 1 0.014kg 0.05 kg 0.595m 12.93s 13.10s 14.6s 20 2 0.014kg 0.1 kg 0.595m 11.53s 11.78s 10.8s 20 3 0.014kg 0.15 kg 0.595m 8.59s 9.37s 9.35s 20 4 0.014kg 0.2 kg 0.595m 8.0s 8.03s 7.72s 20 5 0.014kg 0.1 kg 0.765m 12.97s 13.81 ------- 20 6 0.014kg 0.1 kg 0.50m 10.78s 9.72s ------- 20 7 0.014kg 0.1 kg 0.60m 10.0s 10.25s ------- 20 *For the last 3 trials, we only had time to take 2 time intervals. IV. Analysis and Interpretation 1. Organizing Data- Calculate the weight of the hanging mass for each trial. This weight is the force that maintains circular motion, Fc.
Name: ADEYANJU, ADEBOYE OLUWATOMI Lab section: B02. Rotation: 1 Lab Room#: 206 Locker#: 1171 Date of Experiment 27/01/2015 Time: 8:30 AM Submission date 01/02/15 Experiment 2 Determining the identity of an Unknown Liquid. Purpose The purpose of this experiment is to determine the identity of an unknown substance by calculating; I.) II.) The density, The boiling point.
Part I: Density of Unknown Liquid | | Trial 1 | Trial 2 | Trial 3 | Mass of Empty 10 mL graduated cylinder (grams) | 26.10 | 26.15 | 26.05 | Volume of liquid (milliliters) | 8.69 | 8.50 | 8.31 | Mass of graduated cylinder and liquid (grams) | 37.00 | 36.70 | 36.10 | Part II: Density of Irregular-Shaped Solid | Mass of solid (grams) | 38.954 | 39.068 | 42.885 | Volume of water (milliliters) | 49.9 | 49.9 | 50.0 | Volume of water and solid (milliliters) | 54.1 | 54.1 | 55.0 | Part III: Density of Regular-Shaped Solid | Mass of solid (grams) | 27.50 | 26.70 | 27.40 | Length of solid (centimeters) | 5.25 | 5.00 | 4.50 | Width of solid (centimeters) | 3.00 | 4.00 | 3.50 | Height of solid (centimeters) | 2.50 | 3.00 | 2.00 | Calculations Show all of your work for each of the following calculations and be careful to follow significant figure rules in each calculation. Part I: Density of Unknown Liquid 1. Calculate the mass of the liquid for each trial. (Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder with liquid.) * Trial 1 37.00(g) – 26.10(g) = 10.90(g) * Trial 2 36.70(g) – 26.15(g) = 10.55(g) * Trial 3 36.10(g) – 26.05(g) = 10.05(g) 2.
Freezing Point Depression Hollie Woods & Rebecca Thomas Monday, May 24, 2010 Data and Observations: Table 1: Data for Determining the Freezing Point of Pure Cyclohexane (Part 1) Time (minutes) | Temperature (°C) | 0 | 22.1 | 0.5 | 20.5 | 1 | 15.3 | 1.5 | 11.0 | 2 | 9.5 | 2.5 | 8.7 | 3 | 8.3 | 3.5 | 8.0 | 4 | 8.0 | 4.5 | 7.9 | 5 | 7.9 | 5.5 | 7.8 | 6 | 7.8 | 6.5 | 7.7 | 7 | 7.6 | 7.5 | 7.6 | 8 | 7.6 | 8.5 | 7.6 | 9 | 7.6 | 9.5 | 7.5 | 10 | 7.5 | 10.5 | 7.5 | 11 | 7.5 | 11.5 | 7.5 | 12 | 7.5 | 12.5 | 7.5 | 13 | 7.5 | 13.5 | 7.5 | 14 | 7.5 | 14.5 | 7.1 | 15 | 7.0 | Table 2: Data for Determining the Freezing Point of Naphthalene/Cyclohexane Solution (Part 2) Time (minutes) | Temperature (°C) | 0 | 24.7 | 0.5 | 22.5 | 1 | 19.7 | 1.5 | 16.2 | 2 | 14.6 | 2.5 | 13.5 | 3 | 13.4 | 3.5 | 11.2 | 4 | 11.1 | 4.5 | 8.9 | 5 | 7.5 | 5.5 | 6.5 | 6 | 5.9 | 6.5 | 5.0 | 7 | 4.5 | 7.5 | 4.0 | 8 | 3.4 | 8.5 | 3.0 | 9 | 3.0 | 9.5 | 2.8 | 10 | 2.0 | 10.5 | 2.7 | 11 | 2.1 | 11.5 | 2.0 | 12 | 1.9 | 12.5 | 1.8 | 13 | 1.8 | 13.5 | 1.5 | 14 | 1.5 | 14.5 | 1.5 | 15 | 1.5 | Table 3: Data for Determining the Freezing Point of Unknown/Cyclohexane Solution (Part 3) Time (minutes) | Temperature (°C) | 0 | 23.2 | 0.5 | 16.5 | 1 | 11.0 | 1.5 | 8.1 | 2 | 6.9 | 2.5 | 6.0 | 3 | 5.9 | 3.5 | 5.8 | 4 | 5.5 | 4.5 | 5.2 | 5 | 5.0 | 5.5 | 4.9 | 6 | 4.9 | 6.5 | 4.8 | 7 | 4.8 | 7.5 | 4.2 | 8 | 4.1 | 8.5 | 4.1 | 9 | 4.0 | 9.5 | 4.0 | 10 | 4.0 | 10.5 | 3.9 | 11 | 3.8 | 11.5 | 3.8 | 12 | 3.7 | 12.5 | 3.6 | 13 | 3.6 | 13.5 | 3.5 | 14 | 3.5 | 14.5 | 3.5 | 15 | 3.5 | Calculations: To calculate Freezing point depression between pure cyclohexane and the solution of cyclohexane and naphthalene: Temperature
10. The substance remained in the crucible, above the flame for an extra five minutes on high heat, after the water had evaporated completely. Results Mass of clean, empty crucible and lid | 26.73g | Mass of crucible, lid, and magnesium | 26.87g | Mass of crucible and magnesium oxide | 26.95g | Analysis 1. a) We used 0.14 g of magnesium in the reaction. b) 0.22 g of magnesium oxide was produced. c) 0.08 g of oxygen reacted with the magnesium (0.22 g – 0.14 g = 0.08 g).
The apparent reaction rate was calculated using the equation, kapp= (1/∆t) x ([S2O32-]/[S2O82-]) which resulted in apparent rate constants of 5.66 x 10-5 s-1, 6.1958 x 10-5 s-1, 6.0356 x 10-5 s-1. The actual concentration was calculated using the basic chemical equation, C1V1 = C2V2. In order to find the order of reaction a a graph of log rate vs. log [S2O82-] was drawn, and was found that the results gave a zero order reaction But in reality the reaction order in [I-] and [S2O82-] is in first order each, although [I-] is kept at a constant volume throughout the reaction therefore the overall reaction is pseudo- first order. -d [S2O82-] = kapp [S2O82-] Dt In the second part the rate constant was found using the equation k = (1/∆t) x ([S2O32- ]/[Iodine][S2O82-]). Where it resulted to values of 3.990602 x 10-3 s-1, 4.653278 x 10-3 s-1, 5.944044 x 10-3 s-1, 7.499958 x 10-3 s-1, 7.499958 x 10-3 s-1, 9.84554 x 10-3 s-1, for flasks 4, 5, 6, 7, 8.