friday, 11/19/2010 objective: chromatography lab! get your folder and get ready to start the timed...
TRANSCRIPT
Friday, 11/19/2010
• Objective: Chromatography Lab!
Get your folder and get readyto start the
TIMED BELLRINGER QUESTION.
BELL RINGER
1. How do plants get energy?
2. Why do leaves change colors in the fall?
5 MINUTES
BELL RINGER
1. How do plants get energy?
2. Why do leaves change colors in the fall?
4 MINUTES
BELL RINGER
1. How do plants get energy?
2. Why do leaves change colors in the fall?
3 MINUTES
BELL RINGER
1. How do plants get energy?
2. Why do leaves change colors in the fall?
2 MINUTES
BELL RINGER
1. How do plants get energy?
2. Why do leaves change colors in the fall?
1 MINUTE
TIME’S UP!!!!!
Paper Chromatography
Lab
What is Chromatography?Chromatography is a technique for separating mixtures into their components in order to analyze, identify, purify, and/or quantify the mixture or components.
Separate
• Analyze
• Identify
• Purify
• QuantifyComponentsMixture
Uses for Chromatography
Chromatography is used by scientists to:
• Analyze – examine a mixture, its components, and their relations to one another
• Identify – determine the identity of a mixture or components based on known components
• Purify – separate components in order to isolate one of interest for further study
• Quantify – determine the amount of the a mixture and/or the components present in the sample
Illustration of Chromatography
Mixture Components
Separation
Uses for ChromatographyReal-life examples of uses for chromatography:
• Pharmaceutical Company – determine amount of each chemical found in new product
• Hospital – detect blood or alcohol levels in a patient’s blood stream
• Law Enforcement – to compare a sample found at a crime scene to samples from suspects
• Environmental Agency – determine the level of pollutants in the water supply
• Manufacturing Plant – to purify a chemical needed to make a product
Overview of the Experiment
Purpose: • To explain the relationship between pigments
and photosynthesis.• To predict which pigment colors would be best
for photosynthesis.
• 100 mL beaker• Isopropyl Alcohol (10 mL)• Chromatography paper
strip • Spinach leaf solution
– Red leaf lettuce solution
• Disposable Pipette• Pencil• Ruler• Scissors• Tape
Materials List
Preparing the Chromatography Strips
2. Starting at the line, taper the bottom of the paper with scissors.
3. Place 1-2 drops of the spinach leaf solution on the starting line and allow to dry
1. Draw a line 1.5 cm above the bottom edge of the strip with the pencil
Developing the Chromatograms
• Place the strip in the beaker• Make sure the solution does
not come above the drop on your start line
• Fold the top of the strip over your beaker and tape to keep in place
• Let strips develop for approximately 15 minutes
• Remove the strips and let them dry
• Use the table on your lab handout to analyze your chromatography strip
• Answer the analysis questions in your lab notebook
RESULTS
Debrief/Wrap UpKnowledge of Inquiry
*Scientific investigation begin with a problem but don’t necessarily test a hypothesis
*There is no single scientific method*Inquiry procedures are guided by a question*All scientists performing the same
procedures may not get the same results*Inquiry procedures can influence results*Conclusions must be consistent with the
data*Scientific data is not the same as scientific
evidence*Explanations are developed from the data
and what is known
NOS*Tentativeness*Creativity*Observation vs. Inference*Subjectivity*Theory and law*Socially/culturally
embedded*Empircally based
Suggestions/Comments: