Get Charged Up Part 1- Week 2 Lab Assignment PDF

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Lab Report for Get Charged Up Part 1 Week 2; was given 50/50 points for this assignment....

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Experiment 2 Get Charged Up – Part I Week 2 Total Points: 50 Student’s Name: Jaydyn Fikse Lab Section: 905

REPORT Your report should include the following: •

All data tables (2-3 and 2-4, plus calculations under table 2-4)

•

Answers to questions 1 – 4

•

Data table you constructed in Excel for the Crystallization method

•

Graphs that you constructed in Excel for the Crystallization method o The excel work is worth 10 points

NOTE: You must show your work for all calculations; no work, no credit. Data Table 2-3. Crystallization Method Data (5 pts)

Beaker

Mass of Beaker (g)

Mass of Mg (g)

Mass of Beaker and Salt (g)

Mass of Salt (g)

Limiting Reagent (Mg or HCl)

A

27.928

0.028

28.110

0.182

Mg

B

30.155

0.048

30.413

0.258

Mg

C

29.453

0.076

29.912

0.459

Mg

D

32.015

0.102

32.311

0.296

HCl

E

29.623

0.131

29.996

0.373

HCl

F

29.082

0.159

29.429

0.347

HCl

Data Table 2-2. Crystallization Method Calculations (5 pts) Beaker

Moles of Mg (mol)

Moles of Cl- in Salt (mol)

A

0.001152

0.003823

B

0.001974

0.00542

C

0.003126

0.009642

D

0.004196

0.005472

Experiment 2 Get Charged Up – Part I Week 2 Total Points: 50 E

0.005389

0.006827

F

0.006541

0.005303

Example calculations for beaker A must include: • Grams to moles for Mg (3 pts) •

Mass of MgCl2 to moles Cl- (3 pts)

Molar Mass of Mg = 24.31g

0.028 mol Mg*(1 mol Mg)/(24.31g Mg) = 0.001152 mol Mg

Molar Mass of MgCl2 = 95.21g 0.182g MgCl2*(1 mol MgCl2)/(95.21g MgCl2)*(2 mol Cl-)/(1 mol MgCl2) = 0.003823 mol Cl-

QUESTIONS 1. With regards to the actual procedure, what were the advantages and disadvantages to the titration method and the crystallization method (at least 3)? (3 pts) The advantages of the titration method were that you are working with very precise measurements and it is easier to observe once the reaction has completed due to the change in color. The disadvantages of the titration method were that there was lots of room for human error when determining once that slight color change occurred. The advantages of the crystallization method were that it is also very easy to observe once the reaction has completed because you can physically see the solid forming in the beaker. The disadvantages of the crystallization method were that there is also lots of room for human error while heating up the hydrochloric acid and magnesium strips; if you boil it at too high of a temperature, the liquid could bubble out of the beaker, thus interfering with the precision and accuracy of your measurements.

Experiment 2 Get Charged Up – Part I Week 2 Total Points: 50

2. Based on your results, which method gave more precise results (see definition page 37)? Explain how you determined which method was more precise (Do NOT base your decision on the precision of individual measures, but on the graphical analysis.) (8pts)

The titration method was more precise. The titration r^2 value was 0.9861, while the crystallization r^2 value was 0.9751. The titration r^2 value was closer to 1, thus it gave more precise results.

3. Based on your results, which method gave you more accurate results (see definition page 37)? Explain how you determined which method was more accurate. (8 pts) The titration method was more accurate. The gradient in the titration method was 1.6387, while the gradient in the crystallization method was 2.994. The gradient in the titration method was closer to 2, thus it have more accurate results.

4. Based on your results, what do you tell your supervisor about which method would be better for determining the charge on a metal ion after the metal reacts with HCl? Use your answers to the previous problems to summarize your overall findings. Be sure to include justifications of your finding based on your data and/or calculations. (5 pts) The titration method would be better for determining the charge in a metal ion after it reacts with HCl. The titration method proved to have more precise and accurate results than the crystallization method based on the slope of our graph and its r^2 value. The titration method is also safer and faster to use....