英文滴定实验报告
酸碱滴定实验报告英文
酸碱滴定实验报告英文Titration Experiment ReportAbstract:The objective of this experiment was to determine the concentration of an unknown acid solution using a standard base solution. The titration method was employed, where a base solution, sodium hydroxide (NaOH), of known concentration was slowly added to an acid solution until the pH of the solution reached neutral.Introduction:Titration is a common laboratory technique used to determine the concentration of an unknown solution by reacting it with a solution of known concentration. During the reaction, a pH indicator is used to determine the endpoint of the titration, where the solution reaches a neutral pH. The point at which the titration is complete is called the equivalence point.Materials and Methods:Materials used in this experiment include a burette, pipette, conical flask, pH meter, and indicator. The acid solution to be titrated was provided, labeled as "unknown acid solution." Sodium hydroxide (NaOH) was usedas the base solution, with a known concentration of 0.1 M. A pipette was used to measure 25 mL of the unknown acid solution into the conical flask. The pH meter was calibrated and used to measure the initial pH of the acid solution. The burette was filled with the NaOH solution and slowly titrated into the acid solution while stirring continuously. The pH was continuously monitored until a neutral pH was reached. The volume of NaOH solution used to reach the neutral pH was recorded.Results:The initial pH of the unknown acid solution was measured as 2.8. During the titration, the pH of the solution increased gradually until it reached a neutral pH of 7.0, indicating the completion of the reaction. At this point, the volume of NaOH solution used was recorded as 21.5 mL.Discussion:The concentration of the unknown acid solution can be calculated using the following equation:Concentration of unknown acid solution (mol/L) = Volume of NaOH solution used (L) * Concentration of NaOH solution (mol/L) / Volume of acid solution used (L)Substituting the values from the experiment:Concentration of unknown acid solution = 0.0215 L * 0.1 M / 0.025 L = 0.086 MThe concentration of the unknown acid solution was determined to be 0.086 M.Conclusion:In this experiment, the concentration of an unknown acid solution was successfully determined using a titration method. The unknown acid solution was found to have a concentration of 0.086 M. The accuracy of the experiment could be improved by repeating the titration multiple times and taking an average value.。
酸碱滴定实验英文版Titrating a Hydrochloric Acid solution with a standard sodium hydroxide solution
concentration of standard solution required to complete the titration, we calculate the concentration of the unknown solution. There are several ways in which to express solution concentration. Two commonly used concentration expressions are molarity and normality. The molarity (M, mol L–1) of a solution is the number of moles of solute per liter of solution. The normality (N, equiv L–1) of a solution is the number of equivalents of solute per liter of solution, as shown in Equation 1, in which V is the volume of solution. number of equivalents V (liters)
Background Information
Quality-control personnel in many industries are faced with the task of determining whether or not a process is being satisfactorily carried out, or whether or not a product meets specifications. For example, steel manufacturers use “pickle” baths to remove oxide coatings from their product. Unless the acid concentration in these baths is within a specific range, the pickling process will produce unsatisfactory results. Homeowners with pools or spas use commercial acids to treat the water and clean the filters. Acid concentrations for these products are printed on the labels, and it is essential that the product meet the advertised specifications. Monitoring the acid concentration in a pickle bath or in a commercial acid is critical to the success of the product involved. Titration is a convenient volumetric method for accurately determining the concentration or mass of a component in a solution. Titration involves the addition from a buret of a solution of known concentration, called a standard solution, to a measured volume of a solution of unknown concentration, until the reaction between the solutions is complete. From the stoichiometry of the titration reaction and the volume and
分析化学实验(英文)
Experiment 1PH standard solution preparation and concentration comparisonA Purpose of the experiment1.Learning to master the instrument commonly used in titration of washing and proper use.2.Titration analysis of practice operations through an initial grasp of methyl orange, phenolphthalein indicator end point determination.3.Grasp the pH standard solution preparation method.Two Experimental principle0.1 mol / L HCl solution (strong acid) and0.1 mol / L NaOH solution (alkaline) when each titration, pHsp 7.0, the pH titration jump range of 4.3- 9.7, select the color range in jump indicator ( such as methyl orange, phenolphthalein), can be measured to ensure sufficient accuracy.In the case of the same indicator, a certain concentration of HCl solution and NaOH solution each titration, the ratio of the volume consumed by V HCl / V NaOH should be certain, to, you can test titration technique and the ability to judge the end .Three Main reagents and instruments1. HCl solution of 6 mol / L.2.Saturated NaOH solution (concentration of about15-19 mol /L).3.Methyl orange solution1g / L.4.Phenolphthalein solution of 2 g / L ethanol.Four Experimental procedure1.Solution preparation(1) 0.1 mol / L HCl solution in a clean graduated cylinder to measure small-about8.3 mL 6 mol / L HCl solution was poured into480 mL of water containing about500 mL reagent bottle, add water, diluted to500 mL,covered with glass Cyprus, shaking.(2) 0.1 mol / L NaOH solution in a clean graduated cylinder to measure small about3.3 mL saturated NaOH,poured into480 mL of water containing about500 mL reagent bottle, add water, diluted to500 mL,covered with rubber plug, shake uniform.2.Titration between pH solution(1) with0.1 mol / L NaOH alkaline solution rinse buret2-3times, each time with 5-10 mL solution rinse.And then directly into the alkaline titrant buret in the buret liquid level adjusted to0.00scale.(2) with0.1 mol / L HCl solution, rinse Acid Burette2-3times, each time with5-10 mL solution rinse.And then directly into the acidic titrant in the buret, buret liquid level adjusted to0.00scale.(3)from the buret in the release of alkaline NaOH solution20.00 mL in250 mL conical flask, add2drops of methyl orange indicator, with0.1 mol / L HCl titration to change from yellow to orange.Note reading, parallel to the determination of three.Data record in Table 1, calculate the volume ratio V HCl / V NaOH.(4)from the buret in the release of acidic solution of20.00 mL HCl in250 mL conical flask, add2drops of phenolphthalein indicator, with0.1 mol / L NaOH solution titration to change from colorless to reddish, the red does not maintain the30s fade to end. Note reading, parallel to the determination of three.Data recorded in Table 2, calculate the volume ratio V HCl / V NaOH,and compare the Table1and Table 2, the volume ratio V HCl / V NaOH.Five Data ProcessingIn this study, the data recording and processing are shown in Table1and Table 2..Table 1 HCl NaOH solution titration(using methyl orange as indicator)Table 2 NaOH titration of HCl solution (phenolphthalein as indicator)Six Thinking problems1. HCl and NaOH solution concentration can be accurately prepared me directly?Why?2.Titration analysis in the experiment, buret, pipet titrator and why the need to take to move the solution washed several times Run?Titration flask used have to apply the titrant Run wash?Why?3.Why NaOH titration with HCl using methyl orange as an indicator when, while titration of HCl with NaOH using phenolphthalein as an indicator of when (or other appropriate indicator)?Experiment 2NaOH solution calibration and the determination of total acidity in vinegarA Purpose of the experiment1. To understand base material and potassium dihydrogen phthalate (KHP)the nature of its application.2.Master NaOH standard solution of the preparation, standardization and save points.3.Titration weak acid strong base titration to master the process of jump range and choice of indicator principle.4.To understand the analysis of total acidity of vinegar.Two Experimental principleAcetic acid is an organic weak acid(Ka = 1.8 × 10- 5), and NaOH in the reaction isHAc + NaOH = NaAc + H 2 OReaction product was weak alkali salt, alkaline titration jump in the context of such optional alkaline range of phenolphthalein indicator color.Consumption of acetic acid in vinegar is about30-50 g / L (3- 5%).NaOH standard solution prepared with the calibration method, commonly used potassium dihydrogen phthalate (KHP)as the base material and calibration of its concentration. Calibration reaction is:KHC 8 H 4 O 4 + NaOH = NaKC 8 H 4 O 4 + H 2 OThree Main reagents and instruments1.Saturated NaOH solution (concentration of about15-19 mol /L).2.Phenolphthalein solution of 2 g / L ethanol.3.Potassium dihydrogen phthalate (KHP) standard substance1h at100-125℃ after drying, placed in a desiccator spare.Four Experimental procedure1. 0.1 mol / L NaOH standard solution in the preparation and calibration(1) 0.1 mol / L NaOH solution prepared in a clean small graduated cylinder to measure about 3.3 mL saturated NaOH, poured into480 mL of water containing about500 mL reagent bottle, add water, diluted to500 mL,covered with rubber plug , shake well.(2) 0.1 mol / L NaOH solution to poor calibration of the weighing bottle, weighed KHP three subtraction, each0.4-0.6 g,were poured into250 mL conical flask, adding25-35 mL of water, heating to KHP to dissolve completely.Coolish after blowing flask with distilled water (why?).When completely cooled solution by adding2-3drops of phenolphthalein indicator, calibrated with NaOH solution to be titrated to maintain the30s reddish and shall end not fade.Note the reading, the data records shown in Table 1, calculate the concentration of NaOH solution.2.Determination of total acidity in vinegarPipet25.00 mL of vinegar solution in250 mL conical flask, add2drops of phenolphthalein indicator, titrated with NaOH standard solution changed from colorless to reddish, the red does not fade as the end to keep 30s.Note reading, parallel to the determination of three.Data recorded in Table 2, calculate the total acidity of vinegar, the result in g/100 mL said.Five Data ProcessingIn this study, the data recording and processing are shown in Table1and Table 2..Table 1 NaOH standard solution calibrationTable2Determination of total acidity in vinegarSix Thinking problems1.Calibration standard solution of NaOH the base material used is what?Compared with other benchmark materials, it has any significant advantage?2.Determination of vinegar content, why use phenolphthalein as the indicator? Whether the use of methyl orange or methyl red as indicator?3.Phenolphthalein indicator from colorless to reddish, the solution pH,how many?Red solution in the air, then placed into a colorless why?Experiment 3HCl solution, calibration and determination of total alkalinity of alkali dustA Purpose of the experiment1.Learn anhydrous sodium carbonate and borax base material and the nature of its application.2.Master HCl standard solution of the preparation and calibration procedure.3.To master the dual bases, titration acid titration process of jump range and choice of indicator principle.4.To master the basic elements of quantitative transfer operation.Two Experimental principleAlkaline ash (that is, industrial soda ash) is mainly composed of sodium carbonate, soda brand name, which may also contain a small amount of NaCl, Na 2 SO 4,NaOH and NaHCO and other ingredients.Often HCl standard solution for the determination of total 3alkalinity titrant to measure the quality of the product.Titration reactionNa 2 CO 3 + 2HCl = 2NaCl + H 2 CO 3H 2 CO 3 = H 2 O + CO 2↑Reaction H 2 CO 3is easy to form the supersaturated solution and decomposes to COand escape.Stoichiometric point,pH value of 3.8- 3.9, can be used methyl orange 2as indicator, titrated with HCl standard solution, the solution changed from yellow to orange to end.Sample of NaHCO 3were in the same time and.As the sample is easy to absorb moisture and CO 2,the sample should be dried at270-300℃ 2 h, to remove adsorbed water and to all of NaHCO 3into Na 2 CO 3,alkali dust of the total alkalinity is usually Or Said that as the poor uniformity of samples, moresamples should be weighed to make it more representative.Determination of allowable error may be relaxed.Calibration method using HCl standard solution preparation, often with methyl orange as indicator, with anhydrous Na 2 CO 3as the base material and calibration concentration. Calibration reaction is:Na 2 CO 3 + 2HCl = 2NaCl + H 2 CO 3Can also be used borax(Na 2 B 4 O 7 · 10H 2 O)as the base material, using methyl red as indicator, calibration standard solution of HCl concentration.Calibration reaction is:Na 2 B 4 O 7 · 10H 2 O + 2HCl = 2NaCl + 4H 3 BO 3 + H 2 OThree Main reagents and instruments1. HCl solution of 6 mol / L.2.Anhydrous Na 2 CO 3base material Drying at180℃ for2-3 h later, placed ina desiccator spare.3.Methyl orange solution1g / L.Four Experimental procedure1. 0.1 mol / L HCl standard solution for preparation and calibration(1) 0.1 mol / L HCl solution prepared in a clean graduated cylinder to measuresmall-about8.3 mL 6 mol / L HCl solution was poured into480 mL of water containing about500 mL reagent bottle, add water, diluted to500 mL,cover the glass stopper, shake.(2) 0.1 mol / L HCl solution to poor calibration of the weighing bottle, subtraction, said anhydrous Na 2 CO 3three, each of0.15-0.20 g,respectively, into250 mL conical flask, adding25-35 mL water, heated to completely dissolve Na 2 CO 3.Coolish after blowing flask with distilled water (why?).When completely cooled solution, add2drops of methyl orange indicator to be calibrated with HCl titration solution from yellow to orange as the end point exactly.Note the reading, the data records shown in Table 1, calculate the concentration of HCl solution.2.Alkaline ash Determination of total alkalinityAccurately weighed sample 1.8-2 g and the beaker, add appropriate amount of water, heated to dissolve the sample completely.After cooling, quantitatively transfer the solution to250 mL volumetric flask with water set to the mark, shake it well.Pipet25.00 mL test solution three in250 mL conical flask, adding20 mL water and2drops of methyl orange indicator, titrated with HCl standard solution from yellow to orange as the end point exactly.Note the reading.Data recorded in Table 2, calculate the total alkalinity of the sample, the results indicated by Na 2O%.Five Data ProcessingIn this study, the data recording and processing are shown in Table1and Table 2..Table 1 HCl standard solution for calibrationTable2Determination of total alkalinity of alkali dust (m alkali gray= g)Six Thinking problems1.Why are prepared0.1 mol / L HCl solution,500 mL requirements take 6 mol / L HCl solution of8.3 mL?Write a calculation formula.2.Anhydrous Na 2 CO 3kept properly, absorb the1%water, with this reference material and calibration of the concentration of HCl solution, what the impact on its results?3. When titrated with HCl solution, the use of methyl orange and phenolphthalein indicator to distinguish the two samples are from the Na 2 CO 3-NaOH or Na 2 CO 3-NaHCO 3 composition?4.Demarcation of the two reference substances HCl,Na 2 CO 3and anhydrous borax(NaB 4 O 7 · 10H 2 O)is what advantages and disadvantages of each?2Experiment 4EDTA solution calibration and determination of water hardnessA Purpose of the experimentplexometric titration study the theory and application.2.Grasp the complexometric titration of the direct titration.3.Master EDTA solution preparation and calibration.Two Experimental principleDetermination of water hardness and total hardness of water into calcium - magnesium hardness of the former is to measure the total calcium and magnesium, the latter were measured concentration of calcium and magnesium.Countries in the world that the method of water hardness varies, generally use the degrees (°) said,1°= 10 mg CaO / L.Less than16° for the soft water, greater than16° for the hard water.The total hardness of tap water generally is less than 16°.In addition, China also uses mmol / L or mg / L (CaCO 3)as the unit of water hardness.In this study EDTA complexometric titration of total water hardness.The ammonia in pH10buffer to chrome black T as indicator, with triethanolamine, and Na 2 S masking Fe 3 +, Al 3 +, Cu 2 +, Pb 2 +, Zn 2 +and other ions, with EDTA standard solution titration, can be directly measured total water hardness.Titration reactionCa 2 + + Mg 2 + +Y → CaY + MgYEDTA standard solution prepared with the calibration.In this experiment, chrome black T (EBT)as indicator, as the base material with CaCO 3concentration of calibration.Chrome black T indicator to improve the color of sensitivity, can be added to an appropriate amount of MgY.Calibration reaction is:CaCO 3 + 2HCl = 2CaCl + H 2 CO 3Ca 2 + + MgY +Y → CaY + MgYThree Main reagents and instruments1. EDTA solution0.01 mol / L.2. NH 3-NH 4 Cl buffer solution of pH = 10.CaCO 3reference material dried at110℃, 2 h,coolish placed in the desiccator 3.after cooling to room temperature and set aside.4.Eriochrome Black T indicator 5 g / L (containing 25%triethanolamine and20% Na 2 S).5. HCl solution6mol / L.Four Experimental procedure1. 0.01 mol / L EDTA standard solution for calibrationSubtraction Method in the weighing bottle to accurately weigh0.2-0.3 g CaCO 3,poured into250 mL beaker, add a little water before wetting, cover the surface of dish, from beaker to beaker mouth Department dropping about 5 mL 6 mol / L HCl solution, so that CaCO 3is completely dissolved.Water50 mL,micro boiling a few minutes to remove CO 2.After cooling, rinse the beaker and watch glass, quantitative transfer of CaCOsolution in250 mL volumetric flask with water set to the mark, shake well.Pipet 325.00 mL Ca 2 +solution in the250 mL conical flask, adding20-25 mL water and5-10 mL MgY(obtained from the experiment in step 2), and then adding10 mL NH 3-NHCl buffer solution ,3drops of Eriochrome Black T indicator, immediately EDTA4titration, when the solution stabilized by a wine red to blue purple and then just end shall be.Note reading, measured three times in parallel, the data record shown in Table 1, calculate the concentration of EDTA solution.2.Determination of water hardnessGraduated cylinder to measure water with100 mL in250 mL conical flask, (adding1 -2drops of acid to sample solution, boil a few minutes to remove CO 2.Cooling), by adding10 mL NH 3-NH 4 Cl buffer solution,3drops of Eriochrome Black T indicator, immediately with EDTA titration, when the solution stabilized by a wine red to blue purple and then just shall end.Note reading, measured three times in parallel, the data record shown in Table 2,calculate the total water hardness, results in (°) said. Five Data ProcessingIn this study, the data recording and processing are shown in Table1and Table 2.Table 1 EDTA standard solution for calibrationTable2Determination of water hardnessSix Thinking problems1. EDTA used in this experiment with what indicator should be calibrated? The most appropriate benchmark for material that?2.In the calibration process, adding MgY What is the role?MgY it should be accurate to join?3.In this study, the total hardness in tap water (°) that should be reserved several significant figures? A brief explanation.Five calibration experiments EDTA solution and Bi 3+, Pb2+ content of DeterminationA Purpose of the experiment1.Control the acidity increase by the control theory and application of selective EDTA.2.To master continuous titration with EDTA method.3.Master EDTA solution preparation and calibration.Two Experimental principleMixed ions were commonly used control acidity titration method, masking method can be demonstrated according to the side reaction coefficient of the possibility of their titration, respectively.Bi 3+,Pb2+and EDTA can form a stable1: 1complex,lgK 27.94and 18.04,respectively. Because of the difference lgK vary widely, it can make use of pH effect, control of different acidity, for each titration.At pH ≈ 1时titration Bi 3+, at pH ≈ 5-6时titration of Pb 2+.EDTA standard solution prepared with the calibration.In this experiment, xylenol orange (XO)as indicator, calibrated with ZnO as the base material and its concentration. Calibration reaction is:ZnO + 2HCl = ZnCl 2 + H 2 OZn 2 + +Y → ZnYThree Main reagents and instruments1. EDTA solution0.01 mol / L.2.Hexamethylenetetramine solution of200 g / L.3. ZnO base material and dried at300℃ for 2 h,coolish placed in the desiccator after cooling to room temperature and set aside.4.Xylenol orange (XO) indicator 2 g / L.5. HCl solution of 6 mol / L.Four Experimental procedure1. 0.01 mol / L EDTA standard solution for calibrationSubtraction Method in the weighing bottle to accurately weigh0.16-0.24 g ZnO,into 250 mL beaker, add a little water before wetting, cover the surface of dish, from beaker to beaker mouth Department dropping about5 mL 6 mol / L HCl solution to ZnO completely dissolved.Water20 mL,micro boiling a few minutes.After cooling, rinse the beaker and watch glass, quantitative transfer of Zn 2 +solution in250 mL volumetric flask with water set to the mark, shake well.Pipet25.00 mL solution of the Zn 2 +in250 mL conical flask, dropping hexamethylenetetramine solution to a stable red solution was then over3 mL,then add2drops of xylenol orange indicator immediately with EDTA titration, when the solution stabilized by the purple into a bright yellow orange and then just end shall be.Note reading, three parallel determination, calculated the concentration of EDTA solution.2. Bi 3+, Pb2+ content of DeterminationAccurately pipet Bi 3+,Pb2+test solution was10.0 mL in250 mL three conical flask, add2drops of xylenol orange indicator, titration with EDTA, (adding1-2drops to test solution acidification, boiling minutes to remove CO 2.cooling), by adding10 mL NH 3-NH 4 Cl buffer solution, when the solution from purple through orange and then just turned into a stable bright yellow shall be Bi 3+ in the end.Note reading, calculating mixture of Bi 3+ content results in g / L,said.In the titration of Bi 3+ solution after the adding hexamethylenetetramine solution to a stable red solution was then over3 mL,then add2drops of xylenol orange indicator, and immediately titrated with EDTA,when solution stabilized by the purple into a bright yellow orange and then just shall Pb2+in the end.Note reading, calculating mixture of Pb2+ content, results in g / L,said.Five Data ProcessingIn this study, data records and forms from the column.Six Thinking problems1. EDTA used in this experiment with what indicator should be calibrated? The most appropriate benchmark for material that?2.Why not NaOH, NaAc or ammonia, but with hexamethylenetetramine adjust pH to5 - 6?experiment six Back titration samples of aluminum content in aluminumA Purpose of the experiment1.Grasp the back titration.2.Learn replacement titration.3.Mental and physical, hands-on experimental design.Two Experimental principleAl 3 +is easy to form a series of polynuclear hydroxy complexes, the polynuclear hydroxyl complexes with EDTA complex and slow; the same time,Al 3 +closed indicator xylenol orange, it is usually determined by back titration of aluminum.Quantitative and adding excess EDTA standard solution, boil a few minutes at pH≈ 3.5,so that Al 3 +and EDTA complex completely, then at pH 5- 6, with xylenol orange as indicator, with Zn 2 +salt standard excess of EDTA solution and back titration of aluminum content.Reactive as follows:Al 3 + + Y = AlY (pH≈ 3.5)Zn 2 + + Y = ZnY (pH5- 6)(Indicator has just changed from yellow to purple XO)Three Main reagents and apparatusAluminum nitrate samples; ZnO; HCl (1 +1),(1+3); EDTA (0.01mol / L);xylenol orange(2 g / L);Hexamethylenetetramine(200 g / L);ammonia(1 +1).Four Experimental procedure1 Zn2 + salt standard solution preparationWeigh accurately0.20-0.21 g ZnO in a small beaker, dropping(1 +1) HCl to ZnO completely dissolved, then supplement of1drop (1 +1) HCl, heating, cooling, into250 mL volumetric flask , set the volume, shake and set aside.ZnO calculated according to the quality of the material in the amount of standard solution concentration (in Zn 2 +dollars).2 0.01mol / L EDTA standard solution for preparation and calibrationMeasure out50 mL EDTA solution(0.1mol / L)in the reagent bottle, diluted to500 mL with distilled water around, shake and set aside.Dispense25 mL Zn 2 +standard solution (three) in the conical flask, add2drops of xylenol orange, was added dropwise to the solution of hexamethylenetetramine just become purple, then over 3 mL;with homemade The EDTA titration to the solution just becomes bright yellow for the end, record the volume consumed EDTA solution.According to the data of the exact concentration of EDTA solution.3 Determination of aluminum in aluminum-containing samplesWeigh accurately0.53-0.55 g aluminum nitrate samples in small beaker, add3drops (1 +3) HCl, add the appropriate amount of water dissolved, transferred to a250 mL volumetric flask, volume, shaking.Dispense the Al test solution25 mL(three) in the conical flask, were added50 mL EDTA solution accuracy(about 0.01mol / L), 2drops of xylenol orange, then yellow test solution, add ammonia to the solution was purple, together with(1 +3) HCl solution, the solution yellow.Boiled 3 min,cooling.Add 20 mL of hexamethylenetetramine, then the solution should be yellow, red if the solution must also dropping (1 +3) HCl,to turn plement plus1drop of xylenol orange, Zn 2 +standard solution with flat to just drop into the purple to finish, recording the consumption of Zn 2 +standard solution volume.According to the experimental data of the content of aluminum in aluminum-containing samples (in percentage terms of quality).Five Data recording and processingTable1 EDTA standard solution for calibration(m ZnO = g, c ZnO = mol / L)Table2Determination of aluminum in aluminum-containing samples (G sample= g)The formula is:Six Thinking problems1.For complex alloy sample without replacement titration, while the use of back titration, the result is high or low?2.Back titration with the replacement of EDTA used in titration What is the difference?Experiment 7KMnO 4solution,H 2 O 2calibration and determinationA Purpose of the experiment1.Grasp the KMnO 4solution preparation and calibration process, understand the autocatalytic reaction.2.Master KMnO 4 H 2 O 2determination of the principles and methods.3.On the KMnO 4have experience of the characteristics of its own indicator.Two Experimental principleHydrogen peroxide in the industry, biology, medicine, have a wide range of applications, therefore, often required to determine its practical content.Determination by KMnO H 2 O 2content, often using KMnO 4in sulfuric acid solution standard solution direct 4titration.Titration reaction5H 2 O 2 +2 MnO 4-+ 6 H + =2Mn2+ + 5O2↑ + 8H2 OThe beginning of the slow reaction rate, reaction products to be generated after Mn 2 +, Mn 2 +as a catalyst to accelerate the reaction rate, it can be successfully titrated to a stable reddish presented to the end, so called auto-catalytic reaction.Slightly excessive titrant(2 × 10-6 mol / L)itself purple to display the end.KMnO 4standard solution prepared with the calibration method, often in dilute sulfuric acid solution, at75-85℃, using Na 2 C 2 O 4as the base material, calibration concentration.Calibration reaction is:5C 2 O 4 2-+2 MnO 4-+ 16 H + =2Mn2+ + 10CO2↑ + 8H2 OThe calibration response is autocatalytic reaction, the chemical reaction process should pay attention to acidity, temperature and titration rate.Three Main reagents and instruments1. H 2 SO 4solution of 3 mol / L.Na 2 C 2 O 4reference material Dried at105℃ for 2 h after the backup.2.3. KMnO 4solution of0.02 mol / L.Four Experimental procedure1. KMnO 4solution preparationWeigh KMnO 4solid1.6 g,dissolved in500 mL water, cover the surface of pan, heated to boiling and maintain micro-boiling state 1 h,after cooling, with a porous glass funnel (No.3or 4) filter.Filtrate stored in a brown reagent bottle.The solution at room temperature,2-3days after the filtration reserve.2. KMnO 4solution calibrationSubtraction Method in the weighing bottle to accurately weighed Na 2 C 2 O 4three, each of0.15-0.20 g,respectively, into250 mL conical flask, adding50-60 mL water and 15 mL H 2 SO 4, blowing a small amount of distilled water flask(Why?),heated to75-85℃, hot to be calibrated with a solution of KMnO 4titration.When the reaction began to slow titration, the solution had to be Mn 2 +,the titration speed may be faster, until the solution showed reddish and continued for half a minute does not fade shall end. Data record in Table 1, calculate the concentration of KMnO 4solution.3. H 2 O 2contentAccurate, pipet25.00 mL test solution in250 mL conical flask, three, by adding50 mL water and20 mL H 2 SO 4,KMnO 4standard solution with a titration solution and continued for half a minute showed reddish discoloration shall not end.When the reaction began to slow titration, the solution had to be Mn 2 +,the titration speed may be accelerated.Data recorded in Table 2,calculation of test solution in H 2 O 2content, results in g / L,said.Five Data ProcessingIn this study, the data recording and processing are shown in Table1and Table 2..Table 1 KMnO 4standard solution for calibrationTable2 H 2 O 2contentSix Thinking problems1. KMnO 4solution preparation process to use porous glass filter funnel, how can quantitative filter paper filter?Why?2.Prepared KMnO 4solution should pay attention to?With Na 2 C 2 O 4calibration KMnO 4solution, why start drops of KMnO 4purple disappear slowly?Then they disappear faster and faster, until the endpoint of stability of the purple?3.With KMnO 4 H 2 O 2determination, the ability to use HNO 3, HCl or HAc control of acidity?Why?4.Preparation of KMnO 4solution, the filtration after the filter on the adhesion of the material for that?What material should be used to clean?5. H 2 O 2What are the important properties, should pay attention to what use?Experiment 8CuSO 4 · 5H 2 O in the Cu contentA Purpose of the experiment1.Master Na 2 S 2 O 3solution preparation and calibration points.2.To understand the role of starch indicator principle.3.Indirect iodometric method for the determination to master the principle and operation of copper.4.To understand the decomposition of copper alloy samples.Two Experimental principleCopper alloy sample and CuSO 4 · 5H 2 O in the determination of copper, generally use the iodometric method.In weak acid solution,Cu 2 +and the role of excess KI to generate Cu I precipitation, while precipitation of I 2,titration reactionCu 2 + + 4 I-+ 6 H+= 2 Cu I↓+ I 22Precipitation of I 2,with starch as indicator, with Na 2 S 2 O 3standard solution titration:I 2 + 2 S 2 O 3 2-=2 I-+ S4O62-Cu 2 +and I- the reaction is reversible by adding excess KI, the reduction of Cu 2 + can become completely, but,CuI precipitate strongly adsorbed I 2,then the results will lower.The usual approach is to be incorporated in the near end of thiocyanate, the CuI (Ksp = 1.1 × 10-12)into the solubility of smaller CuSCN (Ksp = 4.8 × 10-15) precipitation, the adsorption of iodine released CuI to respond more fully.ThatCuI + SCN-= CuSCN + I-KSCN near the finish line should be added, or SCN- would restore the abundance of I 2,led to lower measured results.Solution pH should generally be controlled at3.0 -4.0between.Acidity is too low,Cu 2 +easily hydrolyzed, the reaction is not complete, the result is low, and slow reaction rate, the end extension; acidity is too high, then I- oxidation by oxygen in the air as I 2,so that the results high.Determination of copper in copper alloys, the samples of Fe 3 +oxidation of I-,affects the determination, but may be masked by adding NH 4 HF 2.NH 4 HF 2is a good buffer solution, can control the solution pH 3.0- 4.0between.Na 2 S 2 O 3standard solution prepared with the calibration method, often using K 2 CrO 7as the base material, calibration concentration.Calibration reaction is:2Cr 2 O 7 2-+ 6 I-+ 14 H + = 2 Cr 3 + + 3I 2 + 7H 2 OI 2 + 2 S 2 O 3 2-=2 I-+ S4O62-Three Main reagents and instruments1. KI solution of 4%.。
滴定分析基本操作实验报告
滴定分析基本操作实验报告3.2.1 直接法根据所需要的质量浓度（或物质的量浓度），准确称取一定量的物质，经溶解后，定量转移至容量瓶中并稀释至刻度，通过计算即得出标准溶液准确的质量浓度（或物质的量浓度）。
这种溶液也称基准溶液（Standard Solution)。
用来配制这种溶液的物质称为基准物质（StandardSubstance)。
对基准物质的要求是：①纯度高，杂质的质量分数低于 0.02%，易制备和提纯；②组成（包括结晶水）与化学式准确相符；③性质稳定，不分解，不吸嘲，不吸收大气中C02，不失结晶水等；④有较大的摩尔质量，以减小称量的相对误差3.2.2 间接法（也称标定法）若欲配制标准溶液的试剂不是基准物，就不能用直接法配制。
（注意：优级纯或分析纯试剂的纯度虽高，但组成不一定就与化学式相符，不一定能作为基准物使用。
）间接配制法是先粗配成近似所需质量浓度（或浓度）的溶液，然后用基准物通过滴定的方法确定己配溶液的准确质量浓度（或浓度），这一过程称为标定。
一、实验目的1．初步掌握滴定管的使用方法及准确的确定终点的方法。
2．练习酸碱标准溶液的配制。
3．初步掌握酸碱指示剂的选择方法。
二、实验原理滴定分析是将一种已知准确浓度的标准溶液滴加到待测试样的溶液中，直到化学反应完全为止，然后根据标准溶液的浓度和体积求得待测试样中组份含量的一种方法。
O 计量点：pH：7.0；突跃范围：pH：4.3～9.7 NaOH+HCl = NaCl+H2甲基橙（MO）变色范围：3.1（橙色）～4.4（黄色）；酚酞（pp）变色范围：8.0（无色）～9.6（红色）计算：C1V1=C2V2C1/C2=V2/V1强酸HCl强碱NaOH溶液的滴定反应，突跃范围的pH约为4.3～9.7，在这一范围中可采用甲基橙（变色范围pH3.1～4.4）、酚酞（变色范围pH8.0～9.6）等指示剂来指示终点。
间接配制法：酸碱滴定中常用盐酸和氢氧化钠作为滴定剂，由于浓盐酸易挥发，氢氧化钠易吸收空气中的水分和二氧化碳，故此滴定剂无法直接配制，只能先配置近似浓度的溶液然后用基准物质标定其浓度。
滴定实验基础操作实验报告
滴定实验基础操作实验报告实验名称：滴定实验基础操作实验报告一、实验目的1. 掌握滴定实验的基本原理和操作方法；2. 学习使用标准溶液测定未知溶液的浓度；3. 理解滴定曲线的构建方法。
二、实验仪器1. 滴定管：用于滴定溶液；2. Burette（分析滴定管）：用于控制滴定液的加入速度；3. 空气排出装置：用于排出滴定管内的空气；4. 显色剂：用于指示滴定的终点。
三、实验原理滴定实验是一种常见的定量化学分析方法，常用于测定未知溶液的浓度。
其基本原理是通过向溶液中加入一种已知浓度的滴定液，在滴定过程中，从色彩、电位、PH值等方面观察溶液的变化，以确定滴定终点，并进而计算出未知溶液的浓度。
四、实验操作1. 倒取一定体积的未知溶液放入滴定瓶中，加入适量的指示剂；2. 装好分析滴定管（burette），并用标定好的容量管将浓度已知的滴定溶液灌入分析滴定管中；3. 打开滴定管的活塞，使滴定液流至滴定管尖端，并排除空气气泡；4. 缓慢滴加滴定液，同时轻轻搅拌滴定瓶中的溶液，直到观察到明显的颜色变化（滴定终点）；5. 记录滴定液的用量，且要求滴定前后浓度已知的滴定液的体积差不应大于0.03 mL；6. 重复实验两次或以上，计算平均用量。
五、实验结果和数据处理1. 观察滴定终点时滴定液的用量，记为V mL；2. 已知滴定液的浓度为C mol/L，滴定液用量为V mL，则未知溶液的浓度为C ×V mL。
六、实验注意事项1. 滴定终点的判断：滴定终点是指溶液中发生明显的颜色、电位或PH值变化的点。
2. 每次重复实验前，应注意清洗滴定瓶、分析滴定管和容量管，避免交叉污染。
3. 滴定操作时应注意滴定管尖端的液滴不能滴入瓶内，以免引起误差。
七、实验总结通过本次滴定实验，我掌握了滴定实验的基本原理和操作方法。
在实验中，我学会了正确使用滴定管、分析滴定管和容量管，并掌握了排除空气气泡和确定滴定终点的技巧。
通过重复实验和数据处理，我成功地测定了未知溶液的浓度。
滴定重铬酸钾实验报告
滴定重铬酸钾实验报告实验目的本实验旨在通过滴定法测定未知溶液中重铬酸钾（K2Cr2O7）的浓度。
实验原理滴定法是一种常用的定量分析方法，通过溶液的定滴量和滴定液的浓度计算待测物质的浓度。
本实验中，我们使用硫酸铁铵（Mohr's salt，Fe(NH4)2(SO4)2）作为滴定剂，反应方程式如下所示：3Fe(NH4)2(SO4)2 + Cr2O7^2- + 8H+ →3Fe^3+ + Cr^3+ + 6NH4+ + 7H2O + 2SO4^2-在反应过程中，重铬酸钾的钾离子被硫酸铁铵的铁离子氧化成铬离子。
实验步骤1. 取一定量的未知溶液，加入适量的盐酸（HCl）溶解样品中的杂质。
2. 将样品转移到滴定瓶中，加入适量的硫酸铁铵溶液，溶解剂可以使用蒸馏水等纯净水。
3. 用铁铵铬钾指示剂（Diphenylamine sulfonic acid，DPAS）作为指示剂，加入滴定瓶中。
4. 开始滴定，滴定溶液中加入0.1mol/L的硝酸银溶液而出现由橙色变成灰蓝色的终点为滴定终点。
5. 记录滴定瓶中滴加的溶液体积v1，银氨溶液的体积v2。
数据处理1. 用硝酸银溶液滴定终点后，首先计算滴定液体积：Vmoor = v2 - v1。
2. 根据滴定反应方程式，可以计算出待测物质的物质的量n2 = n1 * 3 / 2。
3. 计算待测物质的质量：m2 = n2 * M2。
4. 计算待测物质的浓度：C2 = m2 / V（V为待测物质所置样品的体积）。
实验结果经过滴定实验得到的结果如下所示：- 标准溶液体积v1 = 25.0 mL- 硝酸银溶液体积v2 = 47.5 mL- 待测物质的质量m2 = 1.5 g- 待测物质的浓度C2 = 0.025 mol/L结论与讨论通过滴定法测定重铬酸钾的浓度，我们得到了待测物质的浓度为0.025 mol/L。
实验结果符合预期，并且误差控制在可接受范围内。
在实际实验中，需要注意的是滴定过程中滴定剂和样品的摇匀程度、溶液的容积测量等一些细节操作。
滴定操作实验报告
滴定操作实验报告实验目的本次实验旨在通过滴定操作，测定无机酸和无机碱之间的滴定反应，并确定它们的化学计量比。
实验原理滴定是一种精密的实验操作方法，它是指向反应体系中加入定量的试剂溶液，直至反应完全发生，从而测定被加体系中的待定物质的量的方法。
滴定反应可以反映酸碱的反应特性，根据酸碱滴定反应中酸碱的化学计量比，可以推导分子式，分子量和其它物质化学指标。
实验步骤1. 实验前仪器的准备：使用滴量管、容量瓶、磁力搅拌器、热水槽、普通传递管、分析天平等设备。
2. 称取1.00g的待定物质NaOH，并精确地将其溶解在100mL 的去离子水中。
3. 取出50mL的NaOH溶液装入容量瓶中。
4. 向容量瓶中加入适量的Phenolphthalein指示剂。
5. 取出标准盐酸溶液，并 pipette 成25mL。
6. 向 NaOH 溶液中滴加标准盐酸溶液，同时用磁力搅拌器轻轻搅拌，观察溶液颜色变化。
7. 直到溶液完全变成粉红色，滴定过程结束。
8. 记录加入的盐酸溶液体积。
实验结果在实验中，一开始添加标准盐酸溶液后红色指示剂没有变色，因为NaOH溶液对标准酸的反应不敏感。
但随着加盐酸的数量逐渐增加，最终颜色变成了粉红色，表示反应达到了终点。
记录数据表明，反应需要加入23.50mL的盐酸溶液才能完成。
数据处理与分析据此可以计算出NaOH的摩尔浓度，即：(1.00g / 40.00g/mol) / 0.050L = 0.500mol/L同时，可以通过化学方程式计算出NaOH和HCl的化学计量比是1:1。
实验得出的结果，与理论上计算得出的结果吻合度较高，说明本次实验操作正确、数据准确。
从滴定过程的变化过程来看，盐酸液在NaOH溶液中累积到一定浓度时才会发生反应，表示酸碱反应需要一定的时间才能充分反应，同时提醒我们在实验中更要细心、认真操作。
结论本次实验通过NaOH溶液到标准盐酸溶液的滴定实验来测定了NaOH的摩尔浓度和NaOH与HCl的化学计量比。
化学实验报告英文版
化学实验报告英文版Title: Chemistry Experiment ReportIntroduction:In this experiment, we aimed to investigate the reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl) to understand the concept of neutralization and the formation of a salt and water.Materials:- 50 ml of 0.1 M NaOH- 50 ml of 0.1 M HCl- 100 ml beaker- Stirring rod- pH indicator- Bunsen burner- Safety gogglesProcedure:1. Measure 50 ml of 0.1 M NaOH and pour it into the 100 ml beaker.2. Measure 50 ml of 0.1 M HCl and pour it into a separate 100 ml beaker.3. Add a few drops of pH indicator to the NaOH solution and stir with the stirring rod.4. Carefully pour the HCl solution into the NaOH solution while stirring continuously with the stirring rod.5. Observe any changes in the solution, such as color or temperature.Results:Upon mixing the NaOH and HCl solutions, a neutralization reaction occurred, resulting in the formation of water and sodium chloride (NaCl) salt. The pH indicator changed color from basic to neutral, indicating the completion of the reaction. The solution also produced heat, indicating an exothermic reaction. Discussion:The reaction between NaOH and HCl is a classic example of a neutralization reaction. When an acid and a base react, they neutralize each other, forming a salt and water. In this case, the NaOH and HCl reacted to form NaCl and H2O. The heat produced during the reaction is a result of the exothermic nature of the neutralization reaction.Conclusion:This experiment successfully demonstrated the concept of neutralization and the formation of a salt and water from the reaction between NaOH and HCl. The results were consistent with the expected outcomes, and the experiment was conducted safely and effectively.Overall, this experiment provided valuable insight into the chemical reactions involving acids and bases, and the concept of neutralization in chemistry.。
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英文滴定实验报告
英文滴定实验报告
Introduction
Titration is a widely used technique in analytical chemistry to determine the concentration of a substance in a solution. In this experiment, we aimed to determine the concentration of hydrochloric acid (HCl) by titrating it with a standardized solution of sodium hydroxide (NaOH). The reaction between HCl and NaOH is a classic example of an acid-base reaction, where the acid (HCl) reacts with the base (NaOH) to form water and a salt.
Experimental Procedure
1. Preparation of Standard Solution
To prepare the standardized solution of NaOH, we weighed a specific amount of solid NaOH and dissolved it in distilled water. The solution was then transferred to a volumetric flask and diluted to the mark with distilled water. This ensured that we had a known concentration of NaOH for the titration.
2. Preparation of Acid Solution
In order to determine the concentration of HCl, we prepared a known volume of HCl solution. This solution was then added to a conical flask.
3. Titration Process
Using a burette, we carefully added the standardized NaOH solution to the conical flask containing the HCl solution. We added the NaOH solution drop by drop, while continuously swirling the flask to ensure thorough mixing. The
addition of NaOH was stopped when a color change was observed, indicating the completion of the reaction. This color change was due to the addition of an indicator, phenolphthalein, which is colorless in acidic solutions and turns pink in basic solutions.
4. Data Collection
During the titration process, we recorded the initial and final burette readings to determine the volume of NaOH solution used. This data allowed us to calculate the amount of NaOH required to neutralize the HCl solution.
Results and Discussion
Based on the data collected during the experiment, we calculated the concentration of the HCl solution. By using the equation:
M1V1 = M2V2
where M1 is the concentration of NaOH, V1 is the volume of NaOH used, M2 is the concentration of HCl, and V2 is the volume of HCl used, we were able to determine the concentration of HCl.
By repeating the experiment multiple times and calculating the average concentration of HCl, we ensured the accuracy of our results. The precision of the experiment was evaluated by calculating the standard deviation of the data. Conclusion
In this experiment, we successfully determined the concentration of hydrochloric acid by titrating it with a standardized solution of sodium hydroxide. The use of phenolphthalein as an indicator allowed us to observe the color change at the
endpoint of the titration. The calculated concentration of HCl was found to be consistent with the expected value.
Titration is a versatile technique that can be applied to various acid-base reactions. It provides a quantitative analysis method, allowing scientists to determine the concentration of a substance accurately. This experiment highlights the importance of careful measurement and accurate data collection in analytical chemistry.
Overall, the experiment provided valuable hands-on experience in performing titrations and reinforced the fundamental concepts of acid-base reactions.。