Could you please answer #2 and #3 Coordination Compounds with Copper (II) You wi
ID: 903290 • Letter: C
Question
Could you please answer #2 and #3
Coordination Compounds with Copper (II) You will synthesize a complex salt containing copper and then analyze it using redox volumetric methods and spectrometry to determine the percent composition and ultimately, its empirical formula. You will learn the important technique of titration. There will be two parts to this laboratory experiment: Part I: the synthesis of the complex salt and Part II: the analysis of the complex salt. The laboratory experiment will be performed over a three week period Special mention goes to John Curtin and Nevin Gunduz for developing this laboratory experiment Introduction Ions of the transition elements exist in aqueous solution as complex ions. A complex ion is a metal ion with a molecule called a ligand attached to it through coordinate covalent bonds. A complex salt is an ionic compound but it differs in the fact that there are these covalent bonds attaching the metal to the ligand. The iron(II) ion, for example, exists in water as Fe(H20). The water molecules in this ion are arranged about the iron atom with their oxygen atoms bonded to the metal by donating electron pairs to it. Replacing the H2O molecules witlh six CN ions gives the Fe(CN)6 ion. A coordination compound is a compound consisting either of complex ions and other ions of opposite charge or a neutral species. An example of a coordination compound is the compound K4[Fe(CN)%] which contains the complex ion Fe(CN)% and four K ions. Some of the transition elements have biological activity and their role in human nutrition depends in most cases on the formation of complexes and coordination compounds. 4- In the first part of this experiment, you will make a complex salt containing copper in which water molecules and oxalate ions (C204 act as ligands. This complex salt will be blue in colour. The formula for this complex will have the formula K^Cuy(C204).2H2O where K has a charge of+1, Cu has a charge of +2 and C204 has a charge of -2. After this salt has been prepared you will determine its percent composition in copper and oxalate ion and from this information, determine the values for x, y and z in the formula written above In the synthesis of the complex salt, you will dissolve a copper(II) compound and form the coordination compound. When your coordination compound is crystallized, you can begin the analysis of this compound for the percentage of oxalate and copper(II). The overall reaction for this synthesis is y CuSO4·5H-O + excess reagent K.CUMC20.),' 2H2O + other products It is assumed that CuSO4·5H2O is the limiting reagent and when the number of moles of copper (y) are determined from the percent composition of the coordination compound above, the equation can be balanced and the theoretical yield of this compound can be determined In order to determine the amount of oxalate in your compound, you must know the concentration of the potassium permanganate (KMnO4) solution you are going to use for Part IIB. You must "standardize" or determine the concentration of a KMnO4 solution in Part IIA. You will perform the standardization of a KMnO4 solution by titrating a permanganate solution into a solution containing a known mass of sodium oxalate (Na2C204). The titration reaction is 2+ 5C2042. (aq) + 2 MnO4 (aq) + 16 H. (aq) 10 CO2 (g) + 2 Mn2' (aq) + 8 H20(1) A titration is defined as a procedure for the quantitative analysis of a substance by means of an essentially complete reaction in solution with a reagent of known concentration. The reagent of known concentration in our case is Na2C204. A buret will be used to perform the titration. The buret holds one of the reactants called the titrant and adds this into a reaction vessel which contains the other reactant. The titrant in this experimentExplanation / Answer
2. The generic chemical formula for the coordination compound = K2Cu(C2O4)2 . xH2O
3.
From the reaction
2 moles of KMnO4 react with 3 moles of NaCN
moles of KMnO4 = 3/2 * moles of NaCN
moles of KMnO4 = 1.5 * 0.1009 g / 49 g/mol
moles of KMnO4 = 0.0031 mol
Molarity of KMnO4 = moles / Volume(in L ) = 0.0031 * 1000 / 19.22
Molarity of KMnO4 = 0.161 M