Repeat the titration until there are two titres within 0.1cm3 of each other. Record results in a suitable table. Results: Rough Titre: 7.653 First Run: 6.553 Second Run: 6.453 Third Run: 6.553 Calculations: During the titration, iron(II) ions are oxidised to iron(III) ions and manganate(VII) ions are reduced to manganese(II) ions. The equation is as follows: 5Fe2+(aq) + MnO4-(aq) + 8H+(aq) ? 5Fe3+(aq) + Mn2+(aq) + 4H2O(l) The above equation shows that one mole of manganate(VII) ions reacts with 5 moles of iron(II) ions in acid solution.
What is the molar mass of the antibiotic? Show your work. Data Table 2. Temperature Readings for Freezing Point Time (seconds) |Temp (°C) of control (tap water) |Temp (°C) of solution + 0.5 tsp (~2.5 mL) salt |Temp (°C) of solution + 1.0 tsp (~5 mL) salt | 30 |5|5|2| 60 |5|6|2| 90 |5|4|2| 120 |5|3|2| 150 |5|3|2| 180 |5|3|2| 210 |5|3|2| 240 |5|3|2| 270 |5|3|2| 300 |5|3|2| 330 |5|3|2| 360 |5|3|2| 390|5|3|2| 420 |5|3|2| 450 |5|2|2| 480 |5|3|2| 510 |4|3|2| 540 |4|3|2| 570 |4|3|2| 600 |4|3|2| www.HOLscience.com Colligative Properties and Osmotic Pressure Questions | A. Describe the three freezing points.
A 125mL Erlenmeyer Flask was used to combine (15mL) of concentrated aqueous ammonia and ammonium chloride (0.0467mol, 2.49g). The mixture was stirred till fully dissolved. Colbalt (II) chloride hexahydrate was ground (6.2g) and added in small amounts to the stirring solution (0.0210mol, 5.2g). As the mixture continued to stir (4mL) of 30% hydrogen peroxide was added drop wise to yield a dark warm slurry. After the effervescence, (15mL) of concentrated HCl was added drop wise to the solution.
Calculate the exact normality of Na2S2O3 knowing that in this chemical reaction 1 gram-equivalent of K2Cr2O7 react with 1 gram-equivalent of Na2S2O3 (1 mole K2Cr2O7 react with 6 moles Na2S2O3). Determination of peroxide value. Weigh 3.00 g oil (with precision of 0.001 g) into a 250 ml Erlenmeyer flask. Add 10 ml chloroform and swirl to dissolve oil. Add 15 ml acetic acid,
Design Lab-Chemistry HL Date; 27th February and 1st March 2013 Grade 11 Increasing the temperature to increase the rate of reaction between sulfuric acid and iron powder Experiment; To investigate the effect of temperature of reactants on the rate of reaction Focus Question; How does temperature (30, 35,40,45,50 degrees Celsius) affect the rate of reaction of H2SO4 (1.0M, Volume; 20ml) and Fe (2.5g) in 6 minutes? Fe (s) + H2SO4(l) FeSO4(l) + H2(g) Variables; Independent Variable- Temperature Dependent Variable- how much hydrogen gas is produced Controlled Variable-Sulfuric Acid (1.0M, Volume; 20ml), Iron powder (2.5g), and time (6 minutes) Materials; 3 100ml Flasks 1 cork 1 tube 1 100ml graduated cylinder 1 25ml graduated cylinder 1 clamp stand 1 spatula 1 apron A pair of gloves 1 dropper 1 tub of water 1 waterbath 1 balance scale Stopwatch 3 pieces of paper 2 thermometers 37.5 grams of Iron Powder (Fe) 300 ml of 1.0M H2SO4 Procedure; 1. Wear an apron, gloves and goggles for safety reasons 2. Obtain all materials which are 3 100ml flasks, 1 cork, 1 tube, 1 100ml graduated cylinder, 1 25ml graduated cylinder, 1 clamp stand, 1 spatula, 1 dropper, 1 tub of water, 1 waterbath, 1 balance scale, 1 stopwatch, 2 thermometer to your work place 3. Then obtain 37.5 grams of iron powder, and 300 ml of 1.0M H2SO4 to your work place 4.
ABSTRACT: The purpose of this experiment was to determine the rate constants and ionic strengths of the series and to prove the Bronsted relation. In order to do so, known amounts of KI, Na2S2O3, KNO3, EDTA, starch and K2S2O8 were mixed up, and placed in the spectrophotometer until the %T reached 60%, and time was recorded. In the first part of the calculations, for flask 1, 2 and 3, the true reaction rate was calculated using the equation k = (1/∆t) x ([S2O32-]/[Iodine][S2O82-]). Which resulted in values of 2.8878765.66 x 10-3 s-1 , 3.159845 x 10-3 s-1, and 3.079703 x 10-3 s-1, these values are all similar to each other since they contain no electrolyte reacting with the persulfate solution. 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.
| | | 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
|Mass of crucible and cover | | |Mass of crucible, cover, and alum crystals |25.45g | |Mass of alum crystals |2.0g | |Mass of crucible, cover, and alum after heating #1 |24.55g | |Mass of crucible, cover, and alum after heating #2 |24.55g | |Mass of water driven off |.9g | | |1.15g | |Mass of anhydrous alum, AlK(SO4)2 | | |Moles H2O |.05mol
(b) Calculate the volume of 0.2M UO3- needed to react with 20.00 cm3 of 0.1M Cr2O72-. 3. 24.40 g of hydrated iron(II) sulphate, FeSO4.xH2O was dissolved and made up to 1.0 dm3 of aqueous solution, acidified with sulphuric acid. 25.00 cm3 of the solution was titrated with 20.00 cm3 of 0.022M potassium manganate(VII) solution for complete oxidation. a) Write the equation for the reaction.
The density of concentration was measured using volume and mass and also using different concentrations of liquids. Data Tables: | | | | | | | Data Table 1: Length Measurements | | | | Object | Length (cm) | Length (mm) | Length (m) | | | CD | 12 | 120 | 0.120 | | | Key | 5.3 | 53 | 0.053 | | | Spoon | 16.9 | 169 | 0.169 | | | Fork | 17.7 | 177 | 0.177 | | | | | | | | | | | | | | | Data Table 2: Temperature Measurements | | | Water | Temp (C) | Temp (F) | Temp (K) | | | Hot From Tap | 39 | 102.2 | 375.35 | | | Boiling | 100 | 212 | 485.15 | | | Boiling for 5 min | 100 | 212 | 485.15 | | | Cold from Tap | 26 | 78.8 | 351.95 | | | Ice water-1 min | 6 | 42.8 | 315.95 | | | Ice Water - 5 min | 0 | 32 | 305.15 | | | | | | | | | | | | | | | Data Table 3: Mass Measurements | | | | | | Object | Estimated Mass (g) | Actual Mass (g) |