Prior to the interview, review the plan of study so you are familiar with the degree requirements. This will lead to a more informed conversation about the major during the interview. Make a note of the student's name, major, year at Purdue, and email address to be included in your submitted paper. During the interview, please ask the following questions:
1. Why did you choose this major? Describe the process by which you decided on it.
2. What are the typical major classes like in terms of content, format, and instructor's style of teaching? For example: emphasis on labs/lecture/discussion, small vs. large class sizes, etc.
3. What has been your favorite class? What did you learn, and why was it your favorite?
4. Which classes have been the toughest? What made them tough?
5. What skills and abilities do student need in order to be successful in this major?
6. What are you planning to do after graduation? Do students in this major typically need or want to go to graduate school? What types of careers do student with this major typically go into?
7. What extra-curricular opportunity related to the major have you experienced or can you recommend?
8. One additional thoughtful question of your own in response to the student's previous answers.
Prelab Assignment:
As part of your individual preparation for lab, read the experiment and answer the following questions in your lab notebook. The copy of your answers on the duplicate (yellow) pages is due at the beginning of the lab period. You must attend recitation to receive credit for this assignment.
1. Write the chemical equations, including states of matter, for the two reactions you will perform in lab.
2. Write the molecular formula and calculate the molecular weight (molar mass) of alum, the final solid you will synthesize in this lab. (Alum crystallizes as a dodecahydrate, so include the twelve molecules of water in the formula and the molar mass.)
3. Show your work, including units, for the following series of calculations:
a. How many moles of Al are in 1.25 g of Al?
b. For the synthesis of alum you will be performing in lab, what is the molar ratio of Al to alum? In other words, how many moles of alum are produced from 1 mole of Al?
c. Starting with 1.25 g of Al, what is the theoretical amount of alum (in g) that can be produced if the reaction goes to completion with 100% yield?
d. Calculate the percent yield of alum if a student starts with 1.25 g of Al and produces 14.96 g of alum.
4. Explain, in your own words, the purpose of performing crystallization.
5. Refer to your lab manual to answer (in complete sentences) the following questions about the procedure you will use in lab:
a. Why do you need to use a student bench hood in the preparation of KAl(OH)4?
b. Why are you instructed to clean the surface of the Al(s) before using it in the reaction?
c. What are the grey, tan and/or black particles present after you dissolve the solid Al and how will you remove them?
d. Why is it important to cool the KAl(OH)4 solution to room temperature before adding 9 M H2SO4 to it? What type of reaction occurs in this step?
e. What is the purpose of rinsing the alum with cold ethanol after filtering it?
6. Explain, in your own words, the difference between a gravity filtration and a vacuum filtration. Refer to lab manual Appendix D.
7. Note any safety precautions for this experiment.