(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.
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.
Part C: Density of Sodium Chloride (NaCl) Solution, a sample of NaCl was obtained and measured using a 100mL beaker and a 10mL pipet to determine the concentration of the solution. In order to obtain the appropriate result, a calibration graph and density measurement was used to determine the concentration of the sodium chloride solution. In conclusion, based on the water temperature of 21.8°C in part A’s graduated cylinder experiment obtained, it was determined that the average density was .0973g/mL with a percentage error of 2.5%. When graphed the measurement was equal to Y=0.988x. Part B: The graduated pipet’s average density at 22.3 °C was determined to be 0.9785g/mL with a percentage error of 1.89% shows the graduated pipet to be more accurate and precise.
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them.
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.
Abstract The focus of this experiment was to analyze the kinetics of a nucleophilic substitution. A mixture of 0.3622-M 1-bromopropane and 0.3622-M potassium hydroxide in an 90:10 ethanol/water solvent provided the reactants for a SN2 reaction to occur in a temperature controlled bath at 50.0˚C. The disappearing reactant was found by titrating timed aliquots during the reaction and then measuring the concentration of hydroxide. The k-value was found to be 0.0202 M-1Min-1. Using the linear form of the Arrhenius equation the activation energy was calculated to be 19.9 kcal/mol.
=n (mol)/v (dm3) Whereby c=concentration, n=number of moles and v=volume used. (JOHN GREEN AND SADRU DAMJI, PG 27.THIRD EDITION) Volume=0.1dm3 Concentration of acid =0.0048996mol/0.1dm3 =0.049moldm⁻3 Also, to calculate for the average titre volume of the acid used, I summed up the three consistent values from my experiment and divided it by 3(sarps series, 2009) thus Average Titre volume= (19.60+19.60+19.60) 3 =19.60cm3 Also, to calculate for the concentration of sodium hydroxide, I used The dilution factor, C₁v₁=C₂v₂ (JOHN GREEN AND SADRU DAMJI pg28, third edition) whereby C₁=concentration of the acid used=0.049moldm⁻3 v₁=volume of acid used (titre volume) =19.60cm3 C₂=concentration of the base, v₂=volume of the base used=10cm3 Therefore C₂=
NaCl 1 Na+ and 1 Cl- are formed). Calculate the osmolarity of that solution. What is the molar concentration of ALL particles? e.g. 0.15 M NaCl solution = 0.15 moles of Na+ atoms + 0.15 moles of Cl- atoms = 0.30 Osmoles In other words, the solution is said to have an osmolarity of 0.30 Osm (or 300 mOsm) Assume the osmolarity of the ICF of body cells to be 0.300 Osm (300 mOsm) 2nd, determine if the solute is a PENETRATING particle or is NON-PENETRATING.
This lab exercise focuses attention on the former reaction. Lipid oxidation, which is also called auto-oxidation, occurs in lipid material by way of a free-radical mechanism. After an induction period, hydrogen peroxides, or primary products, are formed. Ultimately these peroxides break down, and secondary products, e.g., aldehydes, ketones, organic acids, and hydrocarbons, are formed. The peroxide value (PV) test, which is one of the most common tests used to evaluate the extent of lipid oxidation, is based on measuring peroxides.
Determination of chemical equilibrium by absorption in the visible region (Fe+3 /SCN System) David KiesseLukwamusu DT203/2 14 Oct 13 Lab Partner: Christiana Poopola Aim: The aim of this experiment is to determine the equilibrium of a compound by using absorption spectrophotometry in the visible region. Procedure: Iron nitrate solution (Fe (NO₃)₃, 0.0166M) and potassium thiocyanate (KSCN, 0.004M) were mixed first together and then with HNO₃ (0.1M) and water in different proportions and solutions. Four solutions were prepared differently as follow: ① Fe(NO₃)₃ (40ml, 0.0166M) was mixed with KSCN (2ml, 0.004M) and three other solution. The equilibrium mixture was made up as follow: Compound | Concentration(M) | Solution A (ml) | Solution B(ml) | Solution C ( ml) | HNO₃ | 0.1 | 25 | 25 | 25 | (FeNO₃)₃ | 0.0166 | 2.5 | 2.5 | 5 | KSCN | 0.004 | 2.5 | 5 | 20 | | | 100 | 100 | 100 | A UV / visible spectra of each solution prepared was recorded with a Shimadzu UV 1601 using PMMA cells to contain the sample. Spectra were collected over the wavelength range 350nm to 800 nm and the absorbance recorded for the peaks observed are detailed in the table below: Results: Solution | Wavelength (nm) | Absorbance | ① | 455 | 0.178 | A | 459 | 0.015 | B | 459 | 0.040 | C | 456 | 0.339 | | | | SCN⁻ initial = (2ml/42ml) x 0.040 M = 1.9 x 10⁻⁴M 1-Calibration: A | FeSCN (M) | Ɛ | 0.178 | 1.9 x 10⁻⁴ | 938.84 | 2- Experiment: Sample | Absorbance | [FeSCN]eq | [Fe+3] eq | [SCN⁻]eq | K | A | 0.015 | 1.6x10⁻⁵ | 3.99x10⁻⁴ | 8.4x10⁻⁵ | 477.4 | B | 0.040 | 4.27x10⁻⁵ | 8.14x10⁻⁴ | 1.57x10⁻⁴ | 333.6 | C | 0.339 | 3.62x10⁻⁴ | 8.3x10⁻⁴ | 4.38x10⁻⁴ | 959.5.