BIOL 1406: LAB EXERCISE 2

Objectives

How do scientists prepare solutions with specific concentrations of solutes?

After completing this exercise, you should be able to:

• define and correctly use the following terms: solute, solvent, solution, aqueous solution, concentration, mole, molar, formula weight, dilution series, parallel dilution, and serial dilution

• prepare a solution of specified volume and concentration from separate solute and solvent

• prepare a solution of specified volume and concentration by diluting a stock solution

• prepare a dilution series using both the parallel and serial dilution methods; and be able to determine which method is most appropriate for preparing a given dilution series

• define optical absorbance and transmittance; and explain how these measurements can be used to assay the concentration of a solution

• explain what a spectrophotometer is; and be able to use one to measure the optical absorbance and transmittance of a solution

• explain the difference between a dependent and an independent variable

• analyze the relationship between two experimental variables using tables, graphs (also called charts), and linear regression analysis

• carry out linear regression analysis for a set of paired numbers and be able to:

  1. determine the linear correlation coefficient for the set of paired numbers

  2. determine the slope and y-intercept of the “best fit” straight line

  3. determine the equation of the “best fit” straight line

  4. calculate the y-value if given the x-value for any point on the “best fit” straight line

  5. calculate the x-value if given the y-value for any point on the “best fit” straight line

  6. plot the “best fit” straight line