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.
The orders of the reaction were 2(n=m=1), k was 0.004174 L mol-1s-1 and the activation energy was 82.577kJ/mol. Introduction: Determination of orders and rate constant The reaction studied is iodide-persulfate reaction, of which the equation is showed below. 2I- + S2O82- I2 + 2SO42- The rate constant (k), and orders (n and m) of the reaction with respect to each of the reactants, in the expression for the rate of reaction R are showed below, R = k [I-]n[S2O82-]m where the square brackets indicate concentrations expressed as moles per liter. In order to determine their values, two sets of experiments need to be carried out. In the first set (part A(i)), the initial rate of reaction will be measured for different reaction mixtures in which the S2O82- concentration is held constant but the concentration of I- is varied.
Oladapo Adaramola Lab # 6 Chemistry equilibrium: Formation constant of a complex ion system Aim: Find the equilibrium concentrations of FeSCN+2 from a graph of absorbance vs. known FeSCN+2 concentrations. Calculate the equilibrium constant (K) for the reaction. Procedure part 1: In order to know the relation between the absorbance of a solution and its concentration, it is necessary for the experimenter to prepare a calibration graph of the molar concentration of FeSCN2+ vs. absorbance. The problem associated with this is that since the reaction is an equilibrium reaction, it has not gone to completion, and the concentration of FeSCN2+ in solution is difficult to determine. Thus, the experiment should “force” the reaction to go almost to completion by the addition of an excess (over 200 times of the amount needed) of Fe3+ ions to a relative small quantity of HSCN.
Based on the Bayle’s Law, the pressure of the gas is inversely proportional to the volume with fixed temperature. Conclusion: Our experimental result shows the slope of our graph of Inverse Volume versus Pressure is 2330 + 15Kpa*ml. We used the slope divided by (R*T), then we are able to find value of n which is n=9.50*10^-4. Our graph is a linear line, which means the product of pressure and volume is a constant (value of slope). Thus we are able to find that the pressure of gas is inversely proportional to the volume with fixed temperature.
(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.
Tissue Papers Absorb Less Liquid in Volume When Concentration of Salt Increases This study was done in an effort to find out the minimum number of papers needed to wipe up a spill so that anyone could prevent wasting paper. In this investigation, sheets of tissue papers were dipped into salt water with different concentrations and soaked until the water traveled to the top, then the amount of water a paper absorbed in terms of both the mass and the volume was recorded. The result showed a strong, positive linear relationship between mass absorbed and salt concentrations, while it showed a slight decrease in volume absorbed with increasing salt concentrations. Further researches could be done to change the substances or even mix different solvents
As for endothermic the reactions pulls in energy and makes it cold to touch. The other experiment measured the pH level in the reaction. The reaction consisted of sodium hydroxide and hydrochloric acid also to see at which point the reaction becomes neutralized. Neutralization is a reaction between an acid and a base forming a salt and water even tho you can’t see the salt due to the salt dissolving into the solution and the pH level of the reaction around level 7 and has a green sometimes yellow colour when the universal indicator is added. The neutralization gap shows how small the gap is to make the reaction neutral.
The consecutive evaporations and condensations allow for the separation and purification of compounds with similar boiling points. Boiling points are directly proportional to pressure; therefore as the pressure is decreased the boiling point will also decrease. Compounds with very high boiling points can be distilled much easier if a vacuum is applied. Vacuum distillation is a common technique which allows for the distillation of high boiling compounds under mild conditions. Both the simple and fractional distillation apparatus can be performed under vacuum by attaching the vacuum line to the fume hood vented adapter near the collection
What is a peroxide killer? After bleaching the cellulosic fiber with hydrogen peroxide, the fiber is subjected a thorough hot wash cold wash and neutralization processes. These operations would remove all superficially available chemicals that were used in bleaching process. However in practice it is found that the core alkali i.e. the alkali due to the use of caustic soda or soda ash and hydrogen peroxide, wetting agents and other auxiliaries would remain in the core of the fiber processed even after 2 or 3 washes.
Experiment 15: Molar Mass Determination by Freezing Point Depression Introduction The purpose of this experiment is to determine the molar mass of camphor by determining the freezing point depression of cyclohexane. In this experiment a sample of the solvent cyclohexane was cooled to its freezing point and a cooling curve was constructed. A known mass of camphor was added to the known mass of camphor and the freezing point of the solution was determined using equations 1 and 2. From the freezing point depression the molality of the camphor can be calculated and then the molar mass, by using equation 3. If Tf(solvent) is defined as the freezing point of the pure solvent, and if Tf(solution) is defined as the freezing point of the solution, then the freezing point depression (in °C) is given by equation 1: ΔTf = Tf(solvent) - Tf(solution) (1) The freezing point depression ΔTf is related to m, the molality of the solution particles, given in equation 2: ΔTf = Kf m (2) If a known mass of a solute is placed into a known mass of solvent, and the freezing point depression relative to the pure solvent determined, then the molar mass (MM) of the solute can be determined by using the appropriate Kf value for the solvent, equation 3: ΔTf = Kf (mol/kg solvent) = Kf (g solute/MM solute) / kg solvent (3) Procedure Determination of the Freezing Point of Cyclohexane A 20 x 50 mm test tube was rinsed clean with cyclohexane.