Chemistry lab report assignment

Chemistry lab report assignment

Topic: Chemistry lab report assignment

I need a lab report due in the hour

Exercise 1 Using pH Paper and the Indicator Bromothymol Blue (BTB)

In this exercise, you will determine the approximate pH for 16 different chemicals using pH paper and BTB.

Common names for chemicals may vary by manufacturer. For this reason, always compare the chemical formulas listed in this lab to those printed on the pipet and bottle labels in your kit.

Procedure

Gather gloves, a sheet of paper, a pencil, two disposable pie pans, paper towels, scissors, the 24-well plate, wide-range pH paper, a trash container, and the Acid-Base Chemistry chemical bag for this experiment.

Create labels for the 24-well plate on the sheet of paper as follows:

Fold the paper in half.

On half of the sheet of paper, place the 24-well plate on the paper and use a pencil to draw around the 24-well plate.

Use the pencil to mark where the wells are positioned in each row and column, marking each side of the wells on the paper drawing. See Figure 4.

Use the edge of the well plate to draw a straight line, connecting the positions of where each well row and well column begins and ends. See Figure 5.

Label the drawing, starting with the first well square in the upper left portion of the grid.

Label the wells 11A–11H and 12A–12H, as shown in Figure 6.

Figure caption is an adequate description of the image.

© 2021 Science Interactive. All Rights reserved.

Figure 6. Labeling the grid 11A–11H and 12A–12H.

Turn the paper so the drawing labeled 11A–11H and 12A–12H is facing upward and place the folded paper in a disposable pie pan. Put the 24-well plate on the piece of paper over the markings. See Figure 7.

Figure caption is an adequate description of the image.

© 2021 Science Interactive. All Rights reserved.

Figure 7. The 24-well plate on the paper over the drawing labeled 11A–11H and 12A–12H.

Open the Acid-Base Chemistry bag and arrange the chemicals in the 24-well plate, with bulbs facing downward, according to the names of chemicals that correspond to each “ID Number”, as listed in Data Table 1. For example, the pipet labeled Acetic Acid (CH3CO2H) will go over the well labeled 11A. See Figure 8.

Figure caption is an adequate description of the image.

© 2021 Science Interactive. All Rights reserved.

Figure 8. Placing the chemicals, bulb face up, in the well plate according to the corresponding “ID Numbers” in Data Table 1.

Place the two pipets containing BTB in two unlabeled wells of the 24-well plate, bulb facing downward. See Figure 9 for complete setup.

Photo of a 24-well plate holding chemical pipets bulb side down over a piece of labeled paper for each well. The paper and well plate are resting in an aluminum pie pan.

© 2021 Science Interactive. All Rights reserved.

Figure 9. Complete setup after step 5.

Before moving on to the experiment, make an educated guess (acid or base) for each chemical by studying the chemical formula, shown in Data Table 1. Record your guess in the column of Data Table 1.

Retrieve the wide-range pH paper, and cut each piece of paper in half lengthwise, and then again in half widthwise. See Figure 10.

Figure caption is an adequate description of the image.

© 2021 Science Interactive. All Rights reserved.

Figure 10. pH paper that has been cut in half lengthwise and width-wise. The final pieces are shown on the right: four pieces have been cut from the single original piece.

Place the cut pieces of pH paper in a pile in a dry location, such as on a sheet of paper, to be used for Exercises 1, 2, and 3.

Note: View the following video for a demonstration of using and reading pH paper before you continue the procedures.

If needed, a descriptive text transcript is available.

Using and Reading Wide-Range pH Paper

©© 2021 Science Interactive. All Rights reserved.

WARNING!

You will be working with strong acids and bases. Do not continue this exercise without wearing protective equipment. You should also wear old clothing that will cover your arms and legs.

Put on your pair of gloves and safety goggles.

Wet a paper towel and place it on the unused disposable pie pan.

Use a pair of scissors to carefully cut off the tip of the first chemical pipet. Cut the pipet over a trash container so the trash container will catch the tip of the pipet.

Replace the pipet, bulb facing downward, back into the 24-well plate in its proper location.

Use the wet paper towel after cutting the pipet to carefully wipe any residue left on the scissors from the chemical.

Repeat steps 10–12, carefully cutting each pipet, one by one, replacing the pipet back in its respective location in the 24-well plate. Wipe off the scissors between each pipet tip cutting.

Keep the used paper towel on the pie pan, but also lay a new, dry piece of paper towel flat in the same pie pan.

Dispense 2 drops of a chemical into its well and then place the pipet bulb down in a disposable cup.

Note: If an air bubble is caught in the tip of the pipet, expel the first drop onto the wet paper towel located in the pie plate. You want each drop that goes into the well plate to be a full drop.

Use one piece of cut pH paper for one well that contains a chemical to determine the approximate pH of the chemical.

Dip the paper into the well and pull it out immediately. It is important to quickly remove the pH paper from the well to avoid dissolving the chemicals from the pH paper into the chemicals in the well.

Then, immediately compare the color of the paper to the scale that was provided with the pH paper.

Record the pH in Data Table 1.

Repeat for each chemical, and only use one sectioned piece of pH paper for one well.

Dispense one drop of BTB in each well of columns 11 and 12.

Record the color of each well in Data Table 1.

Determine whether each chemical was an acid or a base and record your findings in Data Table 1.

Clean up:

Save the chemical pipets for use in Exercise 2.

Save the unused pH paper for use in Exercises 2 and 3.

Clean and dry the 24-well platefor use in Exercise 2.

Exercise 2 Acid-Base Reactions

In this exercise, you will perform a series of reactions between a strong acid and a strong base (SA/SB), a weak acid and a strong base (WA/SB), a diprotic acid and a strong base, and a triprotic acid and a strong base. Based on the stoichiometry of the balanced chemical equations, you will calculate the volume of base that must be added to the final well of each reaction row to reach the equivalence point. An assessment of neutralization will be made using both a pH indicator and universal pH strips.

Procedure

Gather gloves, safety goggles, a sheet of paper, a pencil, a pie pan, paper towels, scissors, the 24-well plate, pH strips from Exercise 1, a trash container, and the chemical pipets used in Exercise 1.

Create labels for the 24-well plate on a sheet of paper as shown in Figure 11. The labels represent the following reactions:

Do you have a similar assignment that you would wish our expert writers from Assignments Proficient to handle for you? Place an order with us on https://assignmentsproficient.com/ and expect the best grades and help from qualified writers

Chemistry lab report assignment Chemistry lab report assignment

 
"Looking for a Similar Assignment? Order now and Get 10% Discount! Use Code "Newclient"