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

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