General chemistry lab

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PynverZnevr2294

Science

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I need help doing a lab form for chemistry. Please show all work for equations! Data is provided in images

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e ore pe and Senthesis of sier Nanoprisms (be sure all stassware is clean) be the large test trates with the numbers-10.-15. and "20", respectively. * 70 each of the tubes add the following solutions: Fins. So ml of the stock sodium citrate solution Second, 50 ml of the stock AgNO, solution Third, 3.0 ml of the stock H.O, solution 3. Shake the tubes to mix the solutions. is critical to the size of the nanoprisms synthesized, so precision is important. The following volumes are + Then, add different volumes of the stock KBr solution and H.O to cach of the tubes. The KBr volume added added: 254L tomKBr and 1.0 ml H,0 to the tube labeled "1.0" + SMERBr and 0.5 mL H2O to the tube labeled "1.5" USB again, shake the tubes to mix. 35uC 200 KBr to the tube labeled "2.0" (no H2O) 6. Finally, add 2.5 mL of the stock NaBH, solution to the first tube only [the borohydride is used to reduce and invert the tube three times to mix (be sure covering is secure to avoid skin contact do not shake the Ag* to Ag(s). Then seal the tube with a stopper or parafilm, place your thumb over the end to seal, 7. A color change should occur in each vial and be complete after about 3 min. Record the color of each vigorously! Repeat this step for the other two tubes (again, one at a time). color by looking at Figures 3 and 4; for example, for a yellow solution, the solution is yellow because the solution. 8. Obtain a small sample (~5 mL) of an “Unknown" nanoprism sample from your instructor. 9. Identify the approximate wavelength of maximum absorbance (Amax) for each sample based on their complement to yellow, or violet, is being absorbed; so the absorbance max is approximately 400 nm. 10. Using your spectrophotometer, determine the absorbance maximum for each nanoprism solution that you synthesized. Repeat for each nanoprism sample; if you are using the same cuvette for each sample, rinse before adding each new sample. 11. Record the color and also determine the absorbance maximum for the “Unknown" nanoprism solution provided to you by your instructor. Data Collection I. Diffraction from hair Hair sample 2: 7706.9 (703.8mm L 5.5mm Vi Yi Hair sample 1: โ 1711.66 mm L 10.9 mm 20.5mm Y2 hair color Brown Y2 Blonde hair color Laboratory 3 Light and Nanotechnology: How Do We "See" Something Too Small to See? lings that were never meant to et Bells of Ireland in Boise, Shoshone. Don't Moscow. ). An Atoms First Approach to the General Chemistry Laboratory, Second Edition 21 II. Synthesis of Silver Nanoprisms Color Nanoprism Sample "1.0" 25 ML "2.5 35 ml "2.0" 4 Sul blue violet yellow Estimated Imax (nm) 640nm coonm 4sonm Measured Imax (nm) 574.0 nm 468.0nm 424.onm Unknown sample 1 Orange 480 nm Soonm 404.onm S22.0nm unknow sample red (violet Analysis DIFFRACTION FROM HAIR 1. Calculate the values of 0, and 4, for each hair sample using Equation 5; show your calculations: Hair sample 1: equation tan(en)=yn/L 8 02 Hair sample 2: 81 82 ugh he lack or were nev last all wint rgy, and me one contair nat promi l'or land Chem 177 Lab Manual on 22 2. Calculate the width of each hair (w) using Equation 4. For each sample you will generate two values (one based on ®, and another based on 82). Then calculate the average width for each hair; show your calculations: Hair sample 1: w (based on :) w (based on 02) = Waverage VIVO Hair sample 2: w (based on 01) w (based on 02) Waverage equation W(STA Wsin(en) and in Boise, пр Мо- of Shoshone. Don't es ur An Atoms First Approach to the General Chemistry Laboratory, Second Edition 23 SILVER NANOPRISMS 1. On the graph below, plot Amax for each synthesized nanoprism sample (y-axis) versus the expected nanoparticle size (x-axis ; from “Average Width” column in Table 2). Then, use a ruler to draw a “best-fit" line to the data (the best-fit line should pass as close as possible to all three data points): 2. Using the best-fit line you have just drawn, estimate the nanoprism size associated with the unknown nanoprism sample (use the Imax you measured for that sample): nanoprism size: Reflection Questions 1. If you were to switch to a green laser pointer (~ = 532 nm) in the diffraction experiment, describe what you would expect to change when you conduct the experiment (assume you stand the same distance from the wall): 3-11 Laboratory 3 Light and Nanotechnology: How Do We "See" Something Too Small to See? 31 my beyim bults, seeds enced in the mountains of Challs, arous place is Embar Lund. but at of Hot herb gunder Another time, failuetu to no bought expensiver Chem 171 Lab Manual in Boise, 2. List the possible sources of error in the diffraction experiment. How would you address each one? 3. What is the color of elemental silver-explain your answer: 4. Which color of light is diffracted at a greater angle from a diffraction grating, red or yellow light? 5. For a substance to look red, describe how it interacts with white light. 6. If the color of a silver nanoparticle solution remains constant, what does that tell you about the tendency of the particles to aggregate under those conditions? Connection Based on your experience in this lab, draw a connection to something in your everyday life or the world around you (something not mentioned in the background section). Laboratory 3 Light and Nanotechnology: How Do We "See" Something Too Small to See? 3-12
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Explanation & Answer

Double check again with theory and I changed the data. The unknowns are OK. The colors from the "standards" of the curve seems in other order. But this does not affect the results 😀

Color EXP
Yellow
Orange-Red
Blue

Color OBS
Blue
Violet
Yellow

Unknow 1
Unknow 2

Orange
Red-Violet

Width Expected (nm)

Max Wavelenght (nm)
20
574
35
468
64
424

66.51655461
29.09425346

404
522

Wavelenght vrs Width
700
600
500
400
300
200
100
0
0

10

20

Make the line trying to conect the first and last value
The value in the middle seems suspicious based on
the color reported (a mixture of colors) and the value

y = -3.1532x + 613.74
R² = 0.8367

Wavelenght vrs Width

30

40

50

60

70

Attached you will find the doc document that review all the answers developed in the discus...


Anonymous
Awesome! Perfect study aid.

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