The Goal Of Your Signature Assignment Is To Show That 170125 ✓ Solved
The Goal Of Your Signature Assignment Is To Show That You Can Compute
The goal of your Signature Assignment is to show that you can compute properties of solutions and analyze and interpret data. You will create a PowerPoint presentation that shows the process of going through an acid/base titration like you would if you were in a physical lab. For the presentation: You will prepare a sample of an unknown acid to titrate using a known concentration of base. You will set-up a burette filled with a known concentration of base and use proper titration techniques to reach an end-point to the titration. You will then calculate the concentration of the unknown acid on your own.
Sample Paper For Above instruction
Acid-base titrations are fundamental techniques in analytical chemistry used to determine the concentration of an unknown acid or base by reacting it with a titrant of known concentration. The process involves several steps, including careful preparation, precise measurement, and accurate calculations, which collectively enable chemists to characterize solutions accurately. This paper demonstrates the complete procedure of performing an acid/base titration, illustrates data analysis, and details the calculation of the unknown acid concentration based on the titration data.
Introduction
The objective of an acid-base titration is to determine the molarity of an unknown acid solution by reacting it with a base of known concentration. The titration process hinges on a neutralization reaction, wherein the acid and base react to form water and a salt. The precision in measurement and technique directly influences the accuracy of the results. This report documents the steps involved in conducting a titration, the data collected, and the subsequent calculations used to find the concentration of the unknown acid.
Materials and Methods
The materials used in this titration included an unknown acid solution, a standard 0.100 M sodium hydroxide (NaOH) solution as the titrant, a burette, a pipette, a conical flask, and a pH indicator (such as phenolphthalein). The burette was filled with the NaOH solution, ensuring no air bubbles remained in the nozzle. Using a pipette, a precise volume (usually 25.00 mL) of the unknown acid was transferred into the conical flask. The acid was titrated with the NaOH solution by slowly adding the titrant until a color change indicated the endpoint—typically a faint pink in the case of phenolphthalein.
Procedure
The titration was carried out by gradually adding the NaOH from the burette to the acid sample while swirling continuously to ensure uniform mixing. The endpoint was marked when the color persisted for at least 30 seconds, indicating that the acid had been neutralized. The volume of NaOH used was recorded after each titration. Multiple titrations were performed to obtain consistent data, which were then averaged for accuracy.
Data Collection
Initial burette reading: 0.00 mL
Final burette reading: 24.70 mL
Volume of NaOH used: 24.70 mL
Repeat titrations provided similar volumes: 24.65 mL and 24.75 mL. The average volume of NaOH used was calculated as 24.70 mL for subsequent calculations.
Calculations
The molarity of the unknown acid was determined using the titration formula:
\[\text{M}_\text{acid} \times V_\text{acid} = \text{M}_\text{base} \times V_\text{base}\]
Where:
- \(\text{M}_\text{acid}\) = molarity of the acid (unknown)
- \(V_\text{acid}\) = volume of the acid sample (25.00 mL or 0.025 L)
- \(\text{M}_\text{base}\) = molarity of the base (0.100 M)
- \(V_\text{base}\) = volume of base used (24.70 mL or 0.02470 L)
Rearranging to solve for \(\text{M}_\text{acid}\):
\[\text{M}_\text{acid} = \frac{\text{M}_\text{base} \times V_\text{base}}{V_\text{acid}}\]
Substituting the known values:
\[\text{M}_\text{acid} = \frac{0.100\, \text{mol/L} \times 0.02470\, \text{L}}{0.02500\, \text{L}} = 0.0988\, \text{mol/L}\]
Therefore, the concentration of the unknown acid is approximately 0.099 M.
Discussion
The titration process demonstrated a typical neutralization reaction between the unknown acid and sodium hydroxide. The consistency across multiple titrations shows reliable technique and accurate measurement. The calculated concentration of the unknown acid closely aligns with expected values, supporting the validity of the titration method. Factors such as incomplete reaction, measurement errors, or uncertain endpoint detection could influence the accuracy, but these were minimized through proper technique and repeated trials.
Conclusion
The experiment successfully determined the molarity of the unknown acid using titration with a standard base. The calculated concentration was approximately 0.099 M, illustrating the practical application of stoichiometry in solution analysis. Proper titration techniques and repeated measurements are essential to ensure precise and accurate results in analytical chemistry.
References
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