Inorganic Chemistry Lab Manual (Al-Nahrain University) PDF

COLLEGE OF SCIENCE / AL-NAHRAIN UNIVERSITY INORGANIC CHEMISTRY LAB MANUAL First stage chemistry 2nd course Edited by Lec.Hadeel Adel As.lec. Marwa Fawzi As.lec Kawther Adeeb As.lec Safa Ismaiel...

COLLEGE OF SCIENCE / AL-NAHRAIN UNIVERSITY INORGANIC CHEMISTRY LAB MANUAL First stage chemistry 2nd course Edited by Lec.Hadeel Adel As.lec. Marwa Fawzi As.lec Kawther Adeeb As.lec Safa Ismaiel 1  Contents Name Page NO. Laboratory Report 3 Laboratory safety practices 4 Glasses and laboratory equipements 6 Experiment 1 Preparation of sodium hydroxide 8 Experiment 2 Purification of table salt 10 Experiment 3 Preparation and reaction of barium 13 peroxide Experiment 4 Calculate the percentage of water in 15 hydrated salt Experiment 5 Paper chromatography 17 Experiment 6 Synthesis of alum from aluminum 20 Experiment 7 Halogens (Group VII B) 23 Experiment 8 Preparation of Calcium Peroxide CaO2 25 Experiment9 Preparation of Copper Iodate and 27 Determination of Its Solubility Product in Water Experiment10 Identification of Oxalate in their Complex as 29 Below 2 Lab Report: 1. Title: a few words which summarize the purpose of the lab 2. Objective: explaining the purpose of the lab. 3. An introduction: a brief summary of what you did. 4. procedure： 5. Discussion: Data analysis, what contributed most to your learning? What didn't work well or was confusing? What would you change? 3 LAPORATORY SAFETY PRACTICES The laboratory is a safe working place when precautions and proper techniques are employed. Your safety practices are as important to your employer or your school as they are to you they are to you since your personal safety, the safety of your fellow workers/students, and the protection of property and equipment are important to them. Most precautions are just common-sense practices. These include the following: 1. Wear safety glasses at all times while in the laboratory. It is the law in this state. 2. Wear shoes at all times. 3. Eating, drinking and smoking are strictly prohibited in the laboratory at all times. 4. Know where to find and how to use safety and first aid equipment 5. Consider all chemicals to be hazardous unless you are instructed otherwise. 6. If chemicals come in contact with your skin or eyes, wash immediately with large amounts of water and then report it to your laboratory instructor. 7. Never taste anything. Never directly smell the source of any vapor or gas; instead, by means of your cupped hand, bring a small sample to your nose. 8. Any reactions involving skin irritating or hazardous chemicals, or unpleasant odors, are to be performed in the fume hood. 9. Never point a test tube that you are heating at yourself or your neighbor since it may splatter out of the opening. No unauthorized experiments are to be performed in the laboratory. 10. Clean up all broken glassware immediately. 11. Always pour acid into water, NOT water into acid, because the heat of solution will cause the water to boil and the acid to splatter. For the 4  same reason, always pour concentrated reagent solutions into diluted reagent solutions 12. Avoid rubbing your eyes unless you are sure your hands are clean. 13. Many common organic reagents such as alcohols, acetone and ether are highly flammable. Do not use them any where near an open flame. 5 6 7 Experiment No.1 Name of exp: preparation of sodium hydroxide Purpous: preparation of sodium hydroxide Theory Sodium hydroxide (NaOH) as known as lye and caustic soda is a metallic base. pure sodium hydroxide is a white solid available in pellets ,flakes ,granules ,and as a 50% saturated solution. It is hygroscopic and readily absorbs water from the air, so it sould be stored in an airtight container. It is very soluble in water with liberation of heat. When using Sodium Hydroxide in the laboratory it must be remembered that Sodium Hydroxide is a strong alkaline. It is frequently used as a neutralizing agent for such processes as waste water treatment. Sodium Hydroxide can also be used as a cleaning agent, especially when mixed with other chemicals. For example, when Sodium Hydroxide is mixed with EDTA for cleaning purposes, the EDTA will remove metallic impurities whilst the sodium hydroxide will dissolve o any fats that are presente Sodium Hydroxide hazards generally relate to the fact that Sodium Hydroxide is classified as a 'Corrosive' substance which can cause severe burns to skin and eyes. It occurs in solid and liquid forms both of which are classified as Hoo Corrosive or Irritant. Solutions are classified as Corrosive to approximately 2% by weight, below which they are toot - o classified as Irritant. Sodium Hydroxide hazards are not always immediately apparent, particularly with regard to the extent of burns caused by Sodium Hydroxide. Skin contact 8 may result in itching rather than the pain of a burn and the destruction of skin tissue tends to be deeper. Sodium Hydroxide is a viscous substance and clings to the skin until washed off thoroughly with water, producing a 'slippery' feeling on the skin surface. Sodium Hydroxide should be washed from the skin immediately to avoid excessive damage. Procedure 1. dissolve (0.74 g) ( mole )of Ca(OH), in 10 ml disteled wate 2. dissolve (1.54 g) ( mole )of Na,COz in 10 ml disteled water 3. Mix the two above solutions and stirred them 4. Filter the precipitate 5. Heat the solution to half volume and then left it to form crystals Ca(OH)2 + Na2CO3 NaOH +CaCO3 Chemicals and glass tools used in the experiment Calcium hydroxide, sodium carbonate distilled water beaker Filter paper funnel Graduated cylinder heater 9 Experiment No.2 Name of exp: purification of table salt Purpous : Pure Sodium Chloride from Common Salt Theory: Salt, also known as table salt, or rock salt, is a mineral that is composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of ionic salts. It is essential for animal life in small quantities, but is harmful to animals and plants in excess. Salt is one of the oldest, most ubiquitous food seasonings and salting is an important method of food preservation. Salt for human consumption is produced in different forms : 1. unrefined salt (such as sea salt) 2. refined salt (table salt), 3. iodized salt.. It is a crystalline solid, white, pale pink or light gray in color, normally obtained from sea water or rock deposits. Edible rock salts may be slightly grayish in color because of mineral content Table salt is already a refined salt, being 99% sodium chloride (NaCI). It usually contains substances (for the other 1%) that make it free-flowing (anti- caking agents) such as sodium silicoaluminate or magnesium carbonate- Calcium sulphate is the most persistent companion of salt. In rock salt, calcium sulphate is sometimes found as anhydrite, hemihydrite or polyhalite Magnesium salts are always present in the sea salt, usually in a ratio of approx. one and a half weight units of magnesium chloride to one weight unit of magnesium- sulphate 11 Procedure: 1- dissolve (1g) of sodium chloride in (5 mi) uf disteid water1g ) 2- add to above solution barium chloride (0.1 M,2.4 g). filter and add to filtrate two drops of barium chloride. 3- add to previous solution (0.1 M, 4.53 g)sodium carbonate and note the change 4- add hydrochloric acid gradually to the filtrate. 5- left the solution until the crystal of salt appears. Chemicals and glass tools used in the experiment Sodium chloride Barium chloride sodium carbonate hydrochloride acid distilled water beaker Filter paper funnel Graduated cylinder 11 Experiment No.3 Name of exp: preparation and reactions of barium peroxide Purpous: 1- knowing the method of preparation 2- knowing the properties of barium peroxide Theory: Barium peroxide is the chemical compound with the formula BaO2. This grey-white solid is one of the most common inorganic peroxides. Barium peroxide is an oxidizing agent, which is used for bleaching. It is used in fireworks as an oxidizer, which also gives a vivid green colour, as do all barium compounds. Barium peroxide is a peroxide, containing O₂ subunits wherein the oxygen atoms bond to each other as well as to the barium. The solid adopts the same structure as calcium carbide, CaC2. Barium peroxide arises by the reversible absorption of O₂ by barium oxide. The oxygen is released above 500°C. 2BaO + O2 2 BaO2 This reaction is the basis for the now-obsolete Brin process for separating oxygen from the atmosphere. Other oxides, e.g. Na₂O, behave similarly." 12 Procedure: A- preparation 1- Dilute (2 ml) of hydrochloric acid (conc.) with (2 ml) of disteled water 2- Add (1.5 g) of barium carbonate in a small portion and may be another amount of carbonate, then heat the solution 3- Filter to separate barium carbonate 4- Dilute (1 ml) of conc. Ammonia with (1 ml) of disteled water and add to it (6 ml) of hydrogen peroxide 5-Cool the solution of peroxide in ice bath and add barium chloride drop by drop with continuous sterring 6-left the solution for one hour-then filter 7-Wash the precipitate with water B-Reactions 1- -put few drops of (0.1 M) KMnO4 in test tube and add to it few amount of BaO2 2- -put a few amount of BaO, in crucible and add to it a few amount of MnO2(powder). Mix the two component and put the crucible on heater until the component of crucible dissolve. Cool and note the colour 3- -put (6-7) drops of AgNO3 in test tube and add to it a few amount of BaO2 (powder) Note the gas evolved and precipitate 13  4- Dissolve amount of BaO2 (0.3 g) in (10 ml) of sulfuric acid (4M) which cool in ice, filter, take the filtrate and add to it (0.1g) Fe and heat the mixture Chemicals and glass tools used in the experiment BaCO3 HCL NH3 H2O2 MnO2 KMnO4 AgNO2 Sulfuric acid Test tube beaker Filter paper funnel Graduated cylinder heater 14 Experiment No.4 Name of exp: Calculate the percentage of water in hydrated salt Purpose: 1- To determine the volume of water content in hydrated salt 2- To determine the formula of hydrated salt. Theory: In crystallography, water of crystallization or water of hydration or crystallization water is water that occurs in crystals. Water of crystallization is necessary for the maintenance of crystalline properties, but capable of being removed by sufficient heat. It is the total weight of water retained by certain salts at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, “water of crystallization “refers to water that is found in the crystalline framework of a metal complex but which is not directly bounded to the metal ion. Upon crystallization from water or moist solvents, many compounds incorporate water molecules in their crystalline frameworks. Compared to inorganic salts, proteins crystallize with unusually large amounts of water in the crystal lattice. A water content of 50% is not uncommon. The extended hydration shell is what allows the proteins crystallographer to argue that the conformation in the crystal is not too far from the native conformation in solution. 15 Procedure: 1. The crucible is heated for a while 2. The crucible are weight with is cover 3. Approximately add (2) gram of hydrated salt, weight and record the data 4. Salt are heat gradually in crucible without its cover for around (3-5) minutes 5. Any colour changes are observed. 6. Stop heating, cover the crucible and wait until cool. 7. Observed 8. Weight 9. The salt need to grind using the glass rode and heat again. 10. The salt need to cool in the room temperature 11. Weight again. Continue heating until the weight constant. *cool the sample in the decicator if needed. 12. The salt temperature are record after the final weight. 13. Add a few drop of water at room temperature, record the temperature. 14. Observed. Chemicals and glassware Hydrated salt crucible 16 Experiment No.5 Name of exp: paper chromatography Purpose: * to observe a technique used by chemists to separate different types of molecules. * to learn about solubility. Theory: Paper chromatography is an analytical chemistry technique for separating and identifying mixtures that are or can be colored, especially pigments. This can also be used in secondary or primary colors in ink experiments. This method has been largely replaced by thin layer chromatography, however it is still a powerful teaching tool. Two-way paper chromatography, also called two-dimensional chromatography, involves using two solvents and rotating the paper 90% in between. This is useful for separating complex mixtures of similar compounds, for example, amino acids. The retention factor (RF) may be defined as the ratio of the distance traveled by the substance to the distance traveled by the solvent. (RF) values are usually expressed as a fraction of two decimal places but it was suggested by smith that a percentage figure should be used instead. If (RF) value of a solution is zero, the solute remains in the stationary phase and thus it is immobile. If (RF) value = 1 then the solute has no affinity for the stationary phase and travels with the solvent front. To calculate the (RF) value, take the distance traveled by the substance divided by the distance traveled by the solvent (as mentioned earlier in terms of ratios). For example, if a compound travels 2.1 cm and the solvent front travels 2.8 cm, (2.1/2.8) the RF value = 0.75. 17 Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires small quantities of material. Separations in paper chromatography involve the same principles as those in thin layer chromatography. In paper chromatography, like thin layer chromatography, substances are distributed between a stationary phase and a mobile phase. The stationary phase is usually a piece of high quality filter paper. The mobile phase is a developing solution that travels up the stationary phase, carrying the sample with it. Components of the sample will separate readily according to how strongly they adsorb on the stationary phase versus how readily they dissolve in the mobile phase. When a colored chemical sample is placed on a filter paper, the colors separate from the sample by placing one end of the paper in a solvent. The solvent diffuses up the paper, dissolving the various molecules in the sample according to the polarities of the molecules and the solvent. If the sample contains more than one color, that means it must have more than one kind of molecule. Because of the different chemical structures of each kind of molecule, the chances are very high that each molecule will have at least a slightly different polarity. Giving each molecule a different solubility in the solvent. The unequal solubilities cause the various color molecules to leave solution at different places as the solvent continues to move up the paper. The more soluble a molecule is, the higher it will migrate up the paper. If a chemical is very non polar it will not dissolve at all in a very polar solvent. This is the same for a very polar chemical and a very non polar solvent. 18 Procedure: 1- Draw a pencil line across a strip of chromatography paper about two centimeters away from one end. Using a drawn-out capillary tube, place a small dot of ink on the paper strip in the center of the line. Prepare two more in the same manner. 2- Using a thin-stem pipet, carefully place 5 to 10 drops of water in the bulb of a jumbo pipet. (BE CAREFUL NOT TO GET ANY LIQUID ON THE INSIDE OF THE STEM OF THE JUMBO PIPET). Prepare two other jumbo pipets similarly, one each with acetone and methanol, labeling them so it is known which solvent is which. Place the jumbo pipets bulb end down in a tube rack. 3. Slip a prepared strip of chromatography paper in reach jumbo pipet so that the end of the paper is in the solvent, but the dot of ink is above the solvent. Place a cork in the top. 4. Observe the color as the solvent travels up the paper by capillary action. Record your observations. Let the separation continue for several minutes, until the solvent nears, but does not reach, the top of the pipet stem. 5. Mark three more strips of chromatography paper (2cm) from one end with pencil. Use a capillary tube to place a small amount of leaf extract at the mark on each strip. Apply two or three times. 6. Run each strip through a separation, one for each solvent. 7. After the acetone strip has dried for several minutes, run it again in methanol. 8. Mark several more strips and try several different. 19 Experiment No.6 Name of exp: Synthesis of alum from aluminum. Purpous: To prepare common alum, K Al (SO4)2.12H2O, from a discarded aluminum Theory: Alums are ionic compounds that crystallize from solutions containing sulfate ion, a trivalent cat-ion such as AL3+, Cr3+ or Fe3+ and a monovalent cat-ion such as K+, Na+ , or NH4. Six of the water molecules bind tightly to the trivalent metal ion; the remaining six molecules bind more loosely to the monovalent cat-ion and the sulfate an-ion. True alums crystallize in well- defined octahedral shapes and money are beautifully colored, particularly those containing d-transition metals. The ancient Egyptians, Greeks, and Romans used alum as a mordant in dyeing cloth. A mordant contains metal ions that bind dyes to the fabric. Presently alum is used to harden photographic film, to prepare pickles, as a mordant, and for other purposes. 21 There are several types of alum: Type of alum Formula Uses (common name) Ammonium NH4Al(SO4)2.12H2O Picking Aluminum sulfate cucumbers Dodecahydrate (ammonium alum) Ammonium ferric sulfate NH4 Fe (SO4)2. 12H2O Mordant in dyeing and printing textiles Dodecahydrate (ferric alum) Potassium K Al (SO4)2. 12H2O Water Aluminum sulfate Purification, Dodecahydrate Sewage treatment, Alum or potassium alum And fire extinguishers Potassium chromium K Cr(SO4)2.12H2O Tanning leather and (III) waterproofing Sulfate fabrics Dodecahydrate (chrome alum) Sodium aluminum Na Al(SO4)2.12H2O Baking powders: Sulfate Hydrolysis of Al3+ releases H+ in 3 water to react with the Dodecahydrate HCO – in baking soda to 2 (sodium alum) produce CO, causing the dough to rise. 21 Procedure: 1- Take aluminum scrap (0.5g) and cut into very small pieces. 2- Place it in a beaker (250 ml) and carefully add potassium hydroxide solution (1.75 g in 15 ml water). 3- Heat the beaker gently and cover it with a watch glass. 4- Continue heating till all the aluminum has dissolved and have an ash- colored solution. (Do not heat to dryness). 5- Filter the warm solution carefully through a thin layer of cotton or glass wool. 6- Cool the solution and add slowly sulphuric acid (15 ml, 6M) with stirring. The solution should give some solid precipitate after the addition of the acid. 7- Heat the solution to dissolve the solids. If the solution is still not clear, filter again while it is warm. 8- Cool the clear solution in an ice bath for 20 min to get the alum crystals. 9- Filter the solution by using a filter paper, dry and determine the yield. 10- Recrystallize the product from water. 22 Exp. 7 Halogens (Group VII B) A- Chlorine Place MnO2 powder into a test tube provided with a gas outlet tube and add as much of concentrated HCl as to cover the MnO, layer. Heat the mixture carefully: 1- Examine the evolving gas using filter paper moistened with: a) Starch solution. b) Starch-iodide solution. c) Moistened litmus paper 2- Note the color of the gas. 3- Collect Chlorine into a test tube containing distilled water. Explain your observations. 4- Write the equations for the reactions of preparation and detection of chlorine. B- Bromine Heat a few drops of bromine water in a test tube. Explain the vapours color and examine by the same steps as in (A-1) Explain your observations and write all the equations. C- Iodine Heat a few portions of iodine crystal in a test tube. Explain the vapours color and examine by the same steps as in (A-1). Explain your observations and write all the equations. D- The dissolution of iodine and Bromine in different solvents Try iodine for solubility in benzene, alcohol, ethyl ether, and triethyl amine Explain the different colors of the solutions. E- Extraction of iodine Dissolve a few crystals of iodine in potassium iodide solution (10%). Add a few drops of chloroform. Explain your observations. 23 F- Oxidation of Iron (II) sulphate Take two separate test tubes containing Mohr's salt (NH4)2SO4. FeSO4. 6H₂O. Add (2-3) drops of bromine water to the first tube and add (2-3) drops of iodine water (KI/I₂) to the second tube. Explain your observations and write all the equations. G- Comparison of the reducing properties of hydrogen halides. (Use the hood!) Put KCI, KBr, and KI into three separate test tubes. Add a few drops of concentrated H2SO4 into each of them and heat slightly. Note the color of the evolving vapours Smell them very carefully and try with Fitmus Write down the reaction equations. H-Reduction of potassium dichromate (K2Cr2O7) Take three separate test tubes containing acidified potassium dichromate solution. Add to the first tube (2-3) drops of potassium chloride (KCI) solution, to the second tube add (2-3) drops of potassium bromide (KBr) solution and to the third tube add (2-3) drops of potassium iodide (KI) solution. Explain your observations and write all the equations 1- Reduction of sodium thiosulphate (Na2S2O3) by bromine water and iodine water Take two separate test tubes containing acidified Na2S2O3 solution, Add to the first tube (5-6) drops of bromine water and add iodine water to the second tube Explain your observations and write all the equations. 2- Action of alkalis on bromine and iodine. (Use the hood!) Add, by drop, a solution of an alkali into a test tube containing liquid bromine for iodine crystals. The solution discolours Now add dilute H 2SO4 to acid reaction and a few drops of benzene. Shake the mixture Explain the phenomena observed. 24 Exp:8 Preparation of Calcium Peroxide CaO2 Calcium peroxide or Calcium dioxide (CaO2) is a solid peroxide with a white or yellowish color. For all practical purposes, calcium peroxide is insoluble in water but it can dissolve in acid to form hydrogen peroxide. When in contact with water it will immediately begin to decompose releasing oxygen. Preparation: Calcium peroxide is created by the interactions of solutions of calcium salt and sodium peroxide, with subsequent crystallization. The octahydrate is synthesized by the reaction of calcium hydroxide with dilute hydrogen peroxide. Applications: Calcium peroxide is manufactured to varying specifications and purity and can be used in different areas of industry and agriculture. In agriculture, it is used as an oxygen fertilizer and is also used in the presowing treatments of rice seeds. Also, calcium peroxide has uses in the aquaculture industry as it is used to oxygenate and disinfect water. and in the ecological restoration industry as it is used in the treatment of soils. Calcium Peroxide is used in a similar manner to magnesium peroxide for environmental restoration programs. It is used to restore soil and groundwater contaminated with petroleum hydrocarbons by stimulating aerobic microbial degradation of the contaminants in a process known as Enhanced In-Situ Bioremediation. As a food additive, it has the E number E930 and is used as a flour bleaching agent and improving agent. 25 The Required Reagents: 1. Calcium carbonate CaCO; (0.5 g). 2. Conc. HCI (2 ml). 3. Hydrogen peroxide (4 ml). 4. Conc. Ammonia. 5. Distilled water. Procedure: 1. Mix in a beaker (2 ml) of distilled water with (2 ml) of conc, HCl, and cover the beaker with a watch glass. 2. Add 0.5 g) of calcium carbonate in a small potion 3. Boit the mixture to expel the produced carbon dioxide, then add (0.5 g) of calcium carbonate until it remains dissolved. 4. Filter the hot solution, then cool the filtrate down, and complete its volume to (2 ml) distilled water. 5. Cool the solution in ice bath, then add (4 ml) of H₂O 60% 6. Prepare (10 ml) of solution of dilute ammonia by adding 18 mli of distilled water, and (2 ml) of conc. Ammonia, then add this solution to the solution mixture of calcium chloride-hydrogen peroxide and stir until calcium peroxide is crystallized. 7. Collect the crystals by filtration then wash them with cold water and dry them at room temperature. 8. Calculate the percentage of the yield. 𝑚𝑎𝑠𝑠 𝑜𝑓 𝐶𝑎𝑂2 Yield % = x 100 𝑡ℎ𝑒 𝑡ℎ𝑖𝑜𝑟𝑦 𝑚𝑎𝑠𝑠 Questions. 1- Write the equation of this reaction 2- Why conc. HCI is used in this experiment? 3- Why ammonia solution is used? 4- Calculate the theory mass of calcium peroxide. 26 Exp. 9 Preparation of Copper Iodate and Determination of Its Solubility Product in Water Procedure: 1. Dissolve (2g) of KIO3 in (25ml) dist. water. 2. Dissolve (0.75g) of Cu(NO3)2.3H₂O in (5ml) of dist. water. 3. Add the saturated solution in step (1) to the solution in step (2) with stirring. Cool and filter the precipitate. Wash with ethanol and dry in an oven (50°C). Cu(NO3)2.3H2O + 2KIO₂ + nH2O Cu(IO3)2.H2O + 2KNO3 + (n-1)H2O Determination of the Solubility Product of Copper Iodate Copper iodate is slightly soluble in water. The concentration of copper ion [Cu+2] and iodate ion [IO3-] in a saturated solution of Cu(IO3)3. H₂O can be calculated by adding an excess of potassium iodide and titrate the librated iodine with a standard solution of sodium thiosulphate (0.1N). Cu(1O3)2 Cu+² + 2IO3 Cu+2 +2I- CuI + 1/2 I2 …………… (1) (IO3- + 5I- + 6H+ 3I2+ 3H2O) x 2 ……… (2) Cu+² +2IO3- + 12I- +12H+ CuI + 6.5I2 + 6H₂O …………. (1+2) I2+ 2S2O3-2 2I- + S4O6-2 S Cu(IO3)2 = [Cu+²] [IO3-]2 = 4[Cu+²]3 27 Determination of Concentration of Copper Ion: 1. Dissolve (0.15g) of Cu(IO3)2.H2O in (10ml.) dist. water with stirring and heat to (50°C). 2. Stir the above solution for (30min.) and filter the product solution. 3. Pipette out (2ml.) of the filtrate then add (0.15g) of potassium iodide (KI) and (1ml.) of acetic acid (2N). 4. Titrate the liberated iodine with (0.IN) sodium thiosulphate in the presence of starch as an indicator 𝑉 𝑁𝑎𝑁𝑎2 𝑆2 𝑂3 × 𝑁 𝑁𝑎𝑁𝑎2 𝑆2 𝑂3 ×103 ×10−3 [Cu+2] = 𝑉Cu(IO3)2.H2O 5. Filter the crystals, wash them with ethanol, and dry them at room temperature 6. Calculate the percentage of the compounds. Questions: 1. Why do we use the KOH solution? 2. Why do we add oxalic acid indirectly? Give the reason. 3. Why do we heat the solution till boiling after adding the aluminum? 4. Draw the structure of the complex. Is this complex stable? Why" Give the hybridization, and geometry of the complex. 5. Give the structure of oxalic C₂O4= 28 Experiment No. (10) Identification of Oxalate in their Complex as Below: Take (1 ml) of the complex solution in a taste tube for each detection by using several indicators. C2O4= + AgNO3 ? C2O4= + BaCl2 ? C2O4= + CaCl2 ? C2O4= + KMnO4 ? ? (15) drops of KMnO4 + (10) drops of Dil. H₂SO₄ Questions: 1- Give an equation for: C2O4= with BaCl2 C2O4= with CaCl2 2- Give the characteristic detection of C2O4= 3- Can we use dil. HCI instead of H₂SO₄? 4- Give the equation of KMnO4 treated with water. 5- Give the properties of KMnO4 29