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Lab 1 Report Sheet For Introduction to Analytical Measurements

Lab report sheet
Course

Quantitative Analytical Chemistry Laboratory (CHEM 2800L )

74 Documents
Students shared 74 documents in this course
Academic year: 2023/2024
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Report Sheet For: Introduction to Analytical Measurements

Name: Ruth-Felicite Irie______________________

All answers must be typed in black ink. Increase the space between questions to insert your answers. The grading rubric is provided separately.

Prelab Question:

  1. Read the description on page 29 (9th, 26) of the textbook on weighing by difference. Write your own description in 25-50 words (add reference for paraphrasing). Remember this should be in your notebook, and it will be in your report too.

The reagent bottle is placed on a balance and tared. The reagent battle is then quickly opened, transferred, and capped again. If a negative reading is scaled after reweighing the bottle, the mass has been delivered.

  1. Read the description on pages 31-32 (9th, 28-29) about weighing errors. Write your own description in 150 -300 words. For this question, you can type it and then print it and cut it out of the paper and tape it into your notebook, rather than writing all of it by hand in your notebook, only to type it for your report.

To reduce vibrations interfering with the scale, the analytical balance should be put on a table made with heavy material. The contents being sealed must be put on the balancing Center for it to be even. If the balance is not properly leveled, errors may occur due to the contents spilling onto the load receptor of the balance. Also make sure the balance is properly calibrated. The glass doors must be close securely, or air can interfere with the balance by removing or adding weight. Before placing heated samples on balance, they should be placed in a desiccator and allowed at least 30 minutes to cool. While the balance is not in use, it should be left in standby mode and room temperature. To avoid adding more mass to the balance with fingerprints use tweezers and napkins two place contents on. Some analytical balances have built-in calibration for the motor and electric current period to help prevent external calibration the mask should be checked from time-to-time period or the standard variation can be found from the trials to also make sure there's no external calibration.

  1. Read the description on pages 32-34 (9th, 29-31) about burets. Answer these questions: a. Define parallax. (up to 30 words)

A parallax is an error that happens when measurements are taking an appropriately. This may happen due to the position of the object appearing to change by looking at it through different positions.

b. Why is black tape on a white card needed? (up to 30 words)

The black tape on a white card is used as a background for finding the exact position of the meniscus. Move the black tape closer to the meniscus and as it approaches the meniscus turns darker.

c. Describe how to deliver a fraction of a drop. (up to 30 words)

to collect a fraction of a drop, open the stopcock slowly until a small part of a drop comes out. Then drop the small part unto the inside wall of the receiving container.

d. Describe how to rinse a buret with new solution. (up to 30 words)

To rinse a buret with new solution, add a small amount of the new solution to the beret and tilt to make sure sufficient contact for all services. Then drain the solution through the tip to ensure rinsing.

  1. Read the description on page 34-35 (9th, 31-32) about Volumetric Flasks. a. Define TC. (up to 10 words)

TC is a label on volumetric flask that tells to contain at 20 degrees Celsius.

b. Define TD. (up to 10 words)

TD is how the pipettes and burettes are calibrated “to deliver” to their indicated volume at 20 degrees Celsius.

c. Define schlieren. (up to 20 words)

Schlieren are streaks in a liquid before it's homogeneous. These streaks arise from regions that refract light differently.

d. Why is swirling of the liquid important? (up to 30 words)

Liquid swirling is important to ensure thorough mixing. Also a small volume change happens when two liquids are mixed.

e. When is the cap/lid/top added to the volumetric flask? (up to 10 words)

When finished making sure the correct amount of fluid is in the flask, then it can be firmly closed.

Experimental and Results

Table 1. The analytical balance. Object Mass to  0 g.

Mean Mass Standard deviation Weigh boat 3 3 0. 3. 3. Filter Paper 0 0 0. 0. 0. Weigh boat + Paper

3 3 0.

3.

3.

Weigh boat + Breath

3 3 0.

3.

3.

Table 2a. The 10-mL Volumetric Pipet.

Temperature Mass H 2 O delivered

Exp. Volume (from Density)

Mean volume

Standard Deviation 20 9 10 9 0. 19 9 9.

19 9 9. 19 9 9. 19 9 9.

Sample Calculation of Density based on Temperature:

Sample Calculation of Experimental Volume based on found Density:

Table 2b. The 25-mL Volumetric Pipet

Beaker Volumetric Flask Graduate Cylinder Erlenmeyer Flask

Below At the line At the line Below

Table 3. Calibration of a Buret Volume Delivered (mL) (VD) (Cumulative)

Mass of H 2 O (g) And beaker Temperature of water: __ 20 ____°C

Mass of 50 mL beaker: 60_ _

Mass of H 2 O (g) (Cumulative)

(mass found minus mass of beaker)

Corrected Volume (CV) based on Density (see Part B) ( two decimal places)

Difference from Corrected Volume and Volume Delivered (CV minus VD), i. Correction (mL) 5 65 5 5 0. 9 70 10 10 0. 15 74 14 14 -0. 20 80 20 20 -0. 25 85 25 25 0. 30 90 30 30 0. 35 95 35 35 0. 39 100 40 40 0. 45 105 45 45 0. 49 110 50 50 0.

Add the Figure produced from the above data that is similar to Figure 2-23 as found on page 45 of the textbook. Give it a title at the bottom of the figure. Ensure that the axes are labeled correctly. In this case, the dots are connected using the scatter function with straight lines and markers. No trendline or equation of the line is added.

Post Lab Questions

  1. In your analysis of Table 1, if the mean mass of the weigh boat is added to the mean mass of the filter paper, does that equal the mean mass of the mass of the weigh boat and the filter paper? Use up to 30-50 words for your answer. If the mean mass of the Weigh boat is added to the mean mass of the filter paper, it does equal to the mean mass of both. When added there are only 3 G but the actual mean mass of the boat and the folks paper equals 3 G.

  2. In your analysis of Table 1, did your breath add any mass to the weigh boat? In your answer that is 30-50 words, describe the precautions that should be taken when using the analytical balance. Chart, blowing breath on the boat does not add mass. The mean mass of both a plain boat and a blowed on boat is 3 grams. Some precautions that should be taken when using the analytical balance are make sure the balance says zero before adding anything. Also, the balance is very sensitive, so make sure the surface is clear of fingerprints.

  3. In your analysis of Table 2a, how close is the mean volume to the expected volume? Discuss the precision and accuracy found for the 10 mL pipet. Use 30- 50 words. According to the analysis, the knee volumes are very close to the expected volumes. The 10 millimeter pipet is accurate and precise. It was accurate because both means are close to one another and it's precise because the pipet increased by about 10 milliliters each time.

  4. Describe your results for Table 2b in 30-50 words. The results showed that different measuring tools will be more precise than others. While all the containers were filled with 100 milliliters of water, only the graduated cylinder and the volumetric flask were at the line.

  5. Based on the figure produced from Table 3. What is the largest correction? What is the smallest correction? The largest correction is 0, and the smallest correction is -0.

  6. Write a concluding statement (30-50 words) for this experiment touching on what was learned and describing the tolerances found for the selected pieces of equipment in comparison to data in the tables found in the textbook. In conclusion, this group of experiments taught about precision and accuracy. It also taught how to use different tools in a lab such as a buret, analytical balance, and the volumetric pipets.

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Lab 1 Report Sheet For Introduction to Analytical Measurements

Course: Quantitative Analytical Chemistry Laboratory (CHEM 2800L )

74 Documents
Students shared 74 documents in this course

University: Kennesaw State University

Was this document helpful?
Report Sheet For: Introduction to Analytical Measurements
Name: ________Ruth-Felicite Irie______________________________
All answers must be typed in black ink. Increase the space between questions to insert
your answers. The grading rubric is provided separately.
Prelab Question:
1. Read the description on page 29 (9th, 26) of the textbook on weighing by
difference. Write your own description in 25-50 words (add reference for
paraphrasing). Remember this should be in your notebook, and it will be in your
report too.
The reagent bottle is placed on a balance and tared. The reagent battle is then quickly
opened, transferred, and capped again. If a negative reading is scaled after reweighing
the bottle, the mass has been delivered.
2. Read the description on pages 31-32 (9th, 28-29) about weighing errors. Write
your own description in 150 -300 words. For this question, you can type it and
then print it and cut it out of the paper and tape it into your notebook, rather than
writing all of it by hand in your notebook, only to type it for your report.
To reduce vibrations interfering with the scale, the analytical balance should be put on a
table made with heavy material. The contents being sealed must be put on the
balancing Center for it to be even. If the balance is not properly leveled, errors may
occur due to the contents spilling onto the load receptor of the balance. Also make sure
the balance is properly calibrated. The glass doors must be close securely, or air can
interfere with the balance by removing or adding weight. Before placing heated samples
on balance, they should be placed in a desiccator and allowed at least 30 minutes to
cool. While the balance is not in use, it should be left in standby mode and room
temperature. To avoid adding more mass to the balance with fingerprints use tweezers
and napkins two place contents on. Some analytical balances have built-in calibration
for the motor and electric current period to help prevent external calibration the mask
should be checked from time-to-time period or the standard variation can be found from
the trials to also make sure there's no external calibration.
3. Read the description on pages 32-34 (9th, 29-31) about burets. Answer these
questions:
a. Define parallax. (up to 30 words)
A parallax is an error that happens when measurements are taking an appropriately.
This may happen due to the position of the object appearing to change by looking at it
through different positions.

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