Lab on Complex Ion Composition Objective The objective of this experiment is to study the continuous variations method that is used to determine the composition of the solution Ni2+ ethylenediamine complexes. Background To examine the interaction between two molecules in solution without isolating the compound Jobfs method is used. Although unstable compounds tend to be generated, this is not a reflection of weak interactions. In some cases, the transition metal species cannot be crystallized from the solution and separated from the other species present. Without Jobfs Method this composition can be very difficult to deduce. Jobfs Method analyzes the value of n in the equilibrium: Z + nL ¨ZLn Varying the n value carries out the experiment. Absorbencies of each of the ZLn complexes are obtained. The sum of the concentrations of the metal, Z, and the ligand, L, are kept equal. With the ratio of the ligand to the metal in the solution with the maximum absorbance for the ZLn complex, the value of n can be determined as well as the composition of ZLn. The metal Ni2+ and the ligand ethylenediamine (en) are studied in this experiment. Solutions are prepared with varying compositions of Ni(en)n2+. Using the equilibrium constants, it is possible to identify which species is present. If the constant for the formation of a species where n is 2 is larger than a species whose constant equals 3 then the former species is pre-dominant. Jobfs Method is limited in that it will give non-integral values of the n present if a fourth complex, ZLn+1, exists. If there is a large variation between the equilibrium constants then only two complexes will be present in the prepared solutions. The absorbance values are plotted, then the value of n can be calculated. Procedure The procedure for this experiment can be found in Inorganic Chemistry Lab Manual prepared by Dr. Virgil Payne. Data and Observations 530 545 578 622 640 0.3 0.079 0.134 0.277 0.555 0.605 0.4 0.088 0.141 0.333 0.596 0.638 0.5 0.099 0.154 0.35 0.57 0.579 0.6 0.158 0.218 0.414 0.584 0.552 0.7 0.212 0.289 0.436 0.459 0.411 0.8 0.376 0.424 0.396 0.203 0.149 0.9 0.213 0.224 0.168 0.061 0.036 1 0.052 0.067 0.142 0.465 0.647 Results and Discssion 1. Ni(en)32+ Ni(en)2(H2O)22+ Ni(en)1(H2O)42+
Physical Chemistry Laboratory Manual, Physical Chemistry Laboratory, Department of Chemistry, University of Kentucky, Spring 2006.
Experimental: The experimental procedure outlined in the OU Physical Chemistry Laboratory Manual was followed without any deviations.
Stability of a complex in solution is known to be the separation of two compound resulting in equilibrium state, theoretically it was observed that; there greater association, the higher the stability of the
Start to prepare the sample in a 10mL (10000µm) place 0.4mL (400µm) of the stock Ferritin solution 0.5g/mL in 0.15M sodium acetate (AcONa). Afterwards add 0.8mL (800µm) at 2M of sulphuric acid (H₂SO₄) and 0.8mL (800µm) at 5mM of dihydroxyfumarate (C₄H₄O₆). Wait for 30 minutes then complement the solution with 1.6mL (1600µm) at 2.5M of sodium acetate (NaOAc) followed by 0.8mL (800µm) at 12.5mM ferrozine (C20H12N4Na2O6S2). Lastly wait another 30 minutes afterwards add distilled water using a stopper to complete the solution to 10mL (10000µm) then put the rubber stopper on the volumetric flask and mix till you are sure that all the contents are mixed. Again, set up the spectrometer to 562nm and using the 2 samples that were made take one from each to measure the absorbance plus a third one from either one of the solution.
The molar absorption coefficient can be found in an absorption spectrum. The absorption spectra is generate...
Before beginning the experiment observe and record the physical appearance of all the chemicals used in the experiment. First write a balanced chemical equation that has Zinc iodide as product when Barium iodide and zinc sulfate are used. To begin today’s lab, weigh a small test tube on a scale that goes to the hundredths place. Using a clean spatula add .45 g + .03 grams of zinc sulfate heptahydrate (.25 g + .03 grams if zinc sulfate is used) into the small test tube. Dissolve the sample in 2 mL of deionized water. Make sure al of the powder is mixed with the water, stopper the test tube and shake for about 1 to 1 ½ minutes to dissolve. Let the test tube stand and weigh another small test tube. Depending on what is being used, .61 g +.03
Solid A was identified to be sodium chloride, solid B was identified to be sucrose, and Solid C was identified to be corn starch. Within the Information Chart – Mystery White Solid Lab there are results that distinguishes itself from the other 4 experimental results within each test. Such as: the high conductivity and high melting point of sodium chloride, and the iodine reaction of corn starch. Solid A is an ionic compound due to its high melting point and high electrical conductivity (7), within the Information Chart – Mystery White Solid Lab there is only one ionic compound which is sodium chloride, with the test results of Solid A, it can be concluded that is a sodium chloride. Solid B was identified as sucrose due to its low electrical
In stoichiometry and this lab, proportions or mass ratios are used to find the quantitative relationships between the reactants and products. Another topic that relate to this lab is the limiting reaction. Stoichiometry was used to find the limiting reaction of this reaction lab through proportions and conversions, which was lead (II) nitrate. Additionally, the excess reactant is another topic that relates to this lab. Stoichiometry was used to find the excess reactant which was potassium iodide. Another topic mentioned was the actual yield. The actual yield was used for lead (II) iodide. This data can be compared to the theoretical yield to find how well the experiment was performed. Additionally, the theoretical yield was used in this lab in order to find the percent yield. Another topic was the percent yield. The higher the percent yield, the better the experiment was performed. Another topic was double replacement. In the experiment the reactants are made of two elements that yields products which have been double replaced. In addition to the previous topics, uncertainty is another topic repeatedly used throughout the lab. The uncertainty is used during measurements to account for the room of error that was possibly made during the measurements. Molar mass was another topic that relates to the lab. In the proportions and conversions part of the lab, molar mass is used to correctly balance the
Gross, R., Abenojar, E. C., & Tan, J. A. (2010) Modern experiments in general chemistry II (3rd ed.). Ateneo de Manila University.
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
2. In the large beaker, put water and boil it completely. After that, remove the beaker from heat. 3. Sample tubes (A-D) should be labeled and capped tightly.
Materials and Methods: An ion exchange chromatography column was obtained and set up for purification with the addition of 0.5 ml ion exchange matrix. 1 ml
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
...ceptor. So this means that the interaction between the Lewis acid metal center in Nickel II perchlorate, Ni(ClO4)2 and the Bronsted base ammonia, NH3, will create a complex. Complex in here means it is a molecular existence formed by two or more element entities (ionic or neutral), or the correlated chemical type. In simpler words, it means that it is a substance that is composed by two or more substances each that can be able to exist independently.
borate) and 1.0 g. of sodium hydroxide in 20 mL of warm water. It may