Thursday, November 13, 2014

Science club/DIY: osmosis

We are working towards our Biology badge and have two experiments. Osmosis with food and capillary action today for the first two challenges.

We are basically doing this experiment...

https://www.youtube.com/watch?v=1072CJu6K60

I put together instructions and questions for the kids as a basic idea since the age and ability range for the kids are so different.


Osmosis with Food Experiment for Biology badge 

Osmosis: The spontaneous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides. 

Equipment - supplies needed
One egg
Vinegar
Light corn syrup Blue food coloring

Distilled water 
Red food coloring 
kitchen scale in grams


Day one
Put raw solid egg in container and add vinegar. Vinegar is a light acid the vinegar will dissolve the calcium carbonate of the shell and leave us with a shell less egg. It will take approx. 24 hours although I have seen it take a little longer. 


Day two –
Remove egg from vinegar and very gently rinse it off. Weigh egg on a kitchen scale and record the weight 


Beginning weight of egg _________________

Add several drop of blue food coloring to light corn syrup. Add Egg to syrup mixture

What do you think will happen to the egg? Why? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
After 24 hours check the egg. Carefully remove egg from the colored syrup.
What happened to the egg? Is it bigger? Smaller? Did it stay the same?
Has the egg changed color? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
Reweigh egg ______________________
What is the difference if any from the beginning weight _________________________________

After observing the egg and any changes add egg to a container containing distilled water and several drops of red food coloring.
What do you think will happen? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
Wait 24 hours and recheck egg.
Has the egg gained, lost or kept the same mass? Did it change color? Why or why not? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
Reweigh egg _____________________________
What, if any, is difference between this weight and the prior weight check? _______________________
Place egg in container with light untinted syrup.
What do you think will happen? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
Wait 24 hours and recheck egg. Before removing egg from syrup do you notice any changes?
What changes, if any, do you see in the egg? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
Reweigh egg __________________ 

FINAL STEP!
Place egg in distilled water with blue food coloring added.

What do you think will happen? _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________
Wait 24 hours and remove egg from water...
What changes, if any, do you see in the egg? Did it change color? Why or why not? Did it change size? Why or why not?
Final egg weight _____________________________
What is the total change, if any, from the beginning weight______________________

Place egg in empty container and gently break open. What color is the inside of the egg? ________________________________________ 


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We are having a  lot of fun with the experiment! We still have the last step todo tomorrow...
the first night (blue egg) the egg lost lots of volume (it lost 50g overnight!) the next day we added in the red food coloring and it actually gained everything back and then some! (it went up to 85g from the original 75g so a 10g gain!)



  Today we put it into the final light syrup stage and final step tomorrow which means Saturday we finish up the experiment. 
Today the kids started off with some drawing...
The kids took turns and read to me and then I read to them. We are about to start the chapter about the sorting hat in Harry Potter. They can't wait to see the movie they think it'll be awesome. Music practice is done for today and Kaitlyn has discovered she needs her own high stool and artist table...

 Dominic sat and looked thru a book with me and I need to run errands (as usual). The girls are making dinner tonight (Shoarma) they can't wait to get started!
 
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