bellwork
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Bellwork. What is concentration? (NOT the kind where you’re thinking really hard…) Why is the orange juice you mix with water called “concentrate”? Draw a picture showing the difference between the molecules in a LOW concentration solution vs a HIGH concentration solution. - PowerPoint PPT PresentationTRANSCRIPT
Bellwork1. What is concentration? (NOT the kind where
you’re thinking really hard…)
2. Why is the orange juice you mix with water called “concentrate”?
3. Draw a picture showing the difference between the molecules in a LOW concentration solution vs a HIGH concentration solution
Egg Lab (In lab book)
Question: How does a cell react to being placed in different concentrations of salt or sugar solutions?
Hypothesis: (leave a blank space- we will come back to this)
Background Information• Cell Membrane is semi-permeable (lets some
thing in, keeps other things out)
• An unfertilized egg is one HUGE cell underneath the hard shell is a semi-permeable cell membrane
Concentration
• Concentration: How close together molecules are in a solution; (amount of solute in an amount of solvent)
• Which beaker has a higher concentration of food coloring?
• Solute- a substance (molecules) that gets dissolved
• Solvent- a fluid that other molecules dissolve in
• Solution- an even mixture of solute and solvent
Egg Lab (In lab book)
Question: How does a cell react to being placed in different concentrations of salt or sugar solutions?
Hypothesis: If, then, as measured by….
Procedures1. Place bowl on scale & zero out2. CAREFULLY add egg to bowl & weigh in grams.
Record.3. In beaker, prepare a ____% ________ solution. First
add ____mL _______, THEN add 200mL ___________
4. Stir solution until all solute is dissolved5. Label beaker with % solute & period# & group #6. Carefully place your egg in solution & leave
overnight in class bin7. Weigh egg again after it has soaked overnight
Procedure #3: Prepare a….
Procedure #3 continued….
5% = FIRST add 10mL (solute) THEN add 200 mL H2O10%= FIRST add 20mL (solute) THEN add 200 mL H2O25%= FIRST add 50mL (solute) THEN add 200 mL HOT H2O50%= FIRST add 100mL (solute) THEN add 200 mL HOT H2O
Lab Group 1 5% salt solutionLab Group 2 10% salt solutionLab Group 3 25% salt solutionLab Group 4 50% salt solution
Lab Group 5 5% sugar solutionLab Group 6 10% sugar solutionLab Group 7 25% sugar solutionLab Group 8 50% sugar solution
Data TableSolution Initial Weight Weight after 24
hrsChange in weight (weight after 24 hrs- initial weight)
Did something move INTO or OUT of the cell?
0% salt (control)
5% salt
10% salt
25% salt
50% salt
0% sugar (control)
5% sugar
10% sugar
25% sugar
50% sugar
Go to the Lab!
• Raise hand to be dismissed from lab & come record your day 1 data @ Ms. D’s computer
18 days until science fair data due
Closure- out loud with group
• Do you think the semi-permeable cell membrane lets salt and/or sugar pass through? Explain why or why not.
(salt breaks apart into Na+ and Cl- charged ions, and sugar-sucrose- is a large carbohydrate macromolecule)
• Predict what will happen to the 0% controls vs the 50% solutions