|
|
| Line 170: |
Line 170: |
| #Before you come to lab next time, read all the material in Lab 2 and outline the day's work in your lab notebook according to the example your instructor went over for Lab 1. | | #Before you come to lab next time, read all the material in Lab 2 and outline the day's work in your lab notebook according to the example your instructor went over for Lab 1. |
| #After reading the material in the Lab 2 wiki, please take the online quiz through Sakai. Your instructor will give you more information about how to take this quiz. | | #After reading the material in the Lab 2 wiki, please take the online quiz through Sakai. Your instructor will give you more information about how to take this quiz. |
| #Make sure that you understand all the concepts covered in Lab 1. Solve the practice problems below on a piece of paper '''(NOT IN YOUR LAB NOTEBOOK!)''' and hand them in at the beginning of lab 2. '''The practice problems must be done individually.''' Your instructor will grade the problems and return them to you in lab 2. | | #Make sure that you understand all the concepts covered in Lab 1. |
| | #Solve the practice problems and submit them through Sakai. A copy of the problems are located below for your convenience. We recommend that you type your answers first in a word document and then paste the answers into Sakai. Assignments will ONLY be accepted through Sakai. Your instructor will show you how to do this in Lab 1. Your instructor will grade the problems and you will receive the results through Sakai. |
| <br> | | <br> |
| '''Practice Problems (10 points)''' | | '''Practice Problems (10 points)''' |
| Line 176: |
Line 177: |
| [[Media:BISC_110_S13_Lab_1_Practice_Problems.doc]] Download Assignment below in Word format through this link<br> | | [[Media:BISC_110_S13_Lab_1_Practice_Problems.doc]] Download Assignment below in Word format through this link<br> |
| <br> | | <br> |
|
| |
| In the following problems, please show all calculations, including the units. To receive full credit, make sure to answer all parts of each question.
| |
|
| |
| #a) How many grams of sucrose (MW=342) would you need to make 100mL of a 10<sup>-2</sup> M sucrose solution? b) How many milligrams of sucrose would you need to make this same solution? c) Express 10<sup>-2</sup> M as a millimolar (mM) concentration.
| |
| #Compound Z has a MW of 100. Your lab partner weighed 25 grams of compound Z and dissolved it in water to a final volume of 1 liter. a) What is the concentration of the solution expressed as a percentage by weight (w/v)? b) What is the concentration of the solution expressed as molarity?
| |
| #Convert a 0.26M solution of cobalt chloride hexahydrate (MW=237.9) into %(w/v) units. b) How would you make a 5% (v/v) solution of ethanol from 100% ethanol?
| |
| #You need to prepare 2 methanol solutions for lab today: a) 300mL of 50% (v/v) methanol and b) 200mL of 25% (v/v) methanol. You have been supplied with 100% methanol and deionized water as well as graduated cylinders and beakers of the appropriate sizes, a magnetic stirrer and Teflon stir bars. How would you use these materials to prepare the two methanol solutions? Note that this question requires more than just showing the math involved. You need to write the steps involved in preparing the solutions, including when and how you use the provided materials.
| |
| #Practice converting between the following units by writing your answers in decimal form and in scientific notation: [[Image:BISC110.1.3.jpg]]
| |
| #You have been given a stock glucose solution with a concentration of 100mg/mL. To perform the glucose assay in lab today, you must dilute the 100mg/mL stock solution of glucose to concentrations of 80mg/mL, 60mg/mL, 40mg/mL, and 20mg/mL. You need to prepare 1mL of each dilution. Explain how you would make the 4 dilutions from the glucose stock solution.
| |
| #The molecular weight of glucose is 180g/mol. To prepare a stock solution of glucose, you dissolve 1.8g of glucose in water to a final volume of 1.0L. This stock solution is then diluted as follows: 50mL of the stock solution is added to 450mL of water, and then 1.0mL of the diluted solution is added to 99mL of water. What is the µM concentration of the final solution?
| |
| #You are writing a research report and you need to describe the concentration of methyl green stain on the ''Tetrahymena'' you show in a photomicrograph. The concentration of methyl green in the bottle was 5% and you added 100 μL of it to 9.9ml of an acidic buffer to make a working dilution of stain. You then combined 10 μL of that diluted stain with 40 μL of your diluted cells and put a few microliters of that mixture on the slide from which you took your photo. What was the effective (final) concentration of the stain?<br><BR>
| |
| <div class=noprint>
| |
|
| |
|
| =='''Links To Other Labs in this Series'''== | | =='''Links To Other Labs in this Series'''== |
