Osmosis Practice SAC 1

A hens egg (normal egg from Coles) undergoes the following;

  1. Remove egg from shell – rinse under tap water – gently dry – and record mass in a data table.  (NB do not attempt to remove any fragments of shell that remain attached to the egg)
  2. Place the egg in a 0.5% NaCl solution and leave for 10 minutes
  3. Remove – dry and reweigh the egg.  Record any other observations
  4. Place the egg in a 2% NaCl solution and leave for 10 minutes
  5. Remove – dry and reweigh the egg.  Record any other observations
  6. Place the egg in 5% NaCl solution and leave for 10 minutes – ensure that the egg is fully covered.
  7. Remove – dry and reweigh the egg.  Record any other observations
  8. Place the egg in 10% NaCl solution for 10 minutes – ensure the egg is fully covered.
  9. Remove, dry and reweigh the egg.  Record any other observations.
  10. Place the egg in the distilled water and leave for 10 minutes – ensure that the egg is fully covered.
  11. Remove, dry and reweigh the egg. Record any other observations.
  12. Collect class data to allow calculation of averages.

Results;

Mass of hen’s egg without the shell =
A) 50.323g
B) 51.33g
C) 50.55g
D) 50.90g
E) 50.43g

Using A) Mass of hen’s egg in distilled water = 59.34g
Using B) Mass of hen’s egg in 0.5% NaCl = 55.34g
Using C) Mass of hen’s egg in 2% NaCl = 52.50g
Using D Mass of hen’s egg in 5% NaCl = 48.48g
Using E) Mass of hen’s egg in 10% NaCl = 47.39g

Table 1;

Construct a table with;

Initial mass, Final mass, Mass change, Percentage change with your varying salt solution.


Discussion questions;

1)  What is control and variable in this experiment?
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2) Why must the egg be covered when immersed in the solution?
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3) Why do we use % mass difference of egg instead of comparing final masses?
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4) What is the purpose of obtaining class data?
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5) Explain what is occuring in the 10% NaCl solution and why the above results are seen.
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