In this case though, finding the molarity of the acid used in the reaction is then used to determine the percent of that acid in a vinegar solution and compared to the standard value for % acid present in vinegar. . The reactions that occurred in during the experiment were neutralization reactions, meaning that the moles of acid equaled the moles base at the end of the experiment. Errors In regards to errors that affected the results o f this experiment, there are many that have contributed to the total 50% error. In order to prevent this error from affecting the results of the experiment, one should attempt to keep the sodium and sodium hydroxide in an enclosed environment at all times, thus limiting the time it has to interact with the atmosphere. In the beginning of the experiment, the volumetric glassware should be clean and dry before used.
In an acid-base titration, a suitable indicator is added to the analyte. Therefore, a buffer solution can be added to the titration chamber to maintain the. Purpose: The purpose of this experiment is to determine the percentage of sugar content in beverages. This value includes the both uncertainties regarding those that applied when the solutions were made eg. . Last Updated Wednesday, September 28, 2005.
At certain volume the light pink color appeared, indicating that titration is done. An appropriate indicator such as phenolphthalein is added to the solution. Titration of an unknown 1. . In addition, the equipment used could have also contributed to the error as all pieces of apparatus have an uncertainty attached to it. Titrant is added to the solution until the analyte permanently changes colour. Titration has similar uses in petrochemical and food industries.
. . However, the exact value of the amount of acetic acid present in a 100mL sample of vinegar is 0. For example, if 3 standards, each with 2. .
Sources of Experimental Error include: The Analytical balance could give wrong reading because of the disturbance due to other students on the shelf it is placed on. The equivalence point is the titrant volume required to react with all I - initially in the sample. Since a change of colorless to light purple was sharp and clear to observe, this could indicate the end-point of the titration Therefore no indicator was necessary in this titration. The acid acetic acid should be mixed in solution with 5. The almost same percentagedifference occurs for next two trials 1. This series of calculations also contributed towards the uncertainty associated with the final answer as each step approximately doubles the % uncertainty. The smooth line was generated using a spreadsheet program.
The algebraic equation representing this fact is called a charge balance equation. These uncertainties can be reduced by using more accurate equipments, for example a more accurate mass balance. Titration is a process of adding a standard solution to a solution of unknown concentration 2. A generic chemical reaction for titrimetric analysis is where a moles of analyte A contained in the sample reacts with t moles of the titrant T in the titrant solution. When we calculated the molarity of the acetic solution, an average value of 0. The calculations are easily performed using a spreadsheet program. The accuracy of the measurement the volumes is the degree of closeness… 1265 Words 6 Pages Joanna Park Mrs.
A bit about how one may we obtain the smooth line is discussed below. The volumetric glassware, measuring cylinder and pipette should be handled with care and all the precautions… 1715 Words 7 Pages Torres 1 Luis A. Methods of determining when the analyte has been consumed include: - detecting a sudden change in the voltage or current between a pair of electrodes - monitoring a spectrophotometric absorbance change - observing an indicator color change 1. V is the volume of the analyte, typically in liters. One goal of this course is to introduce you to the record keeping methods used in research labs. When the reaction involves oxidation and reduction, the method is referred to as a redox titration.
Here are some important considerations that apply in research settings… 746 Words 3 Pages Chemistry Practical Investigation-Volumetric Analysis Discussion: Based on the data obtained, the precision of obtaining the data is high. The total silver ion added to the solution is The amount of excess silver ion is the that amount added, less the amount reacted The total solution volume is volume is 25. Human judgment also accounts for some of the error in this experiment as the person performing the experiment was required to read off many measurements from the pipette and burette. Weigh to nearest milligram 2. One might notice that the four points do not unambiguously give the smooth line plotted.
As the titration progressed, we watched the graph on the computer and saw the pH increase and then rise very slowly. Because of the rapid pH change around the equivalence point, the titrant has to be added in lesser and lesser amounts as we approach the equivalence point. Thus, the final answer did not match the theoretical value accurately because the strength was weakened, meaning that the numbers used to calculate the molar concentration were not as accurate. A chemical analysis that is performed primarily with the aid of volumetric glassware e. Procedure: Begin the procedure by first making sure all glassware has been cleaned. The precipitation titration proceeds via the chemical reaction K sp for AgI is only 8. Dumas burned a sample of a compound with known weight in a furnace under conditions that ensured the conversion of all nitrogen into elemental nitrogen gas or N2.
The pH rises above the equivalence point because we are adding base to a solution with a relatively large volume. Results and Calculations 69 O. This error can be reduced by always ensuring that readings are always made at eye level and that the same person taking the readings is constant as judgment varies with each person. . Conclusion In conclusion, this experiment found the molar concentration of acetic acid in vinegar to be 0. .