CBA Science: 30th April 2018 - Present by Bill O'Dwyer https://padlet.com/16bodwyer/yfz25cnbgz How corrosive are certain liquids against old coins? en-us 2018-04-30 14:56:16 UTC 2026-03-08 20:41:50 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Thunder.png Research Question 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256555565
  • How corrosive are certain liquids against old and dirty coins?
    • ]]>     2018-04-30 15:09:35 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256555565     Equipment 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256581268
  • Liquids (Water, Milk, Coca Cola, Vinegar)
  • 4 old coins
  • A measuring Cylinder
  • 4 separate beakers
  • 4 separate test tubes
  • A test tube holder
  • Parafilm and marker
  • iPad Camera
    • ]]>     2018-04-30 15:56:18 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256581268     Hypothesis 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256777688
  • I think the coins would come out cleaner then they were before they went into the test tube with vinegar and coca cola
    • ]]>     2018-05-01 07:46:08 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256777688     Method 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256777769
  • Get 4 old coins and take a picture of them before you put them in the test tubes.
  • Measure 30 cm3 of each liquid using the measuring cylinder and pour them into separate test tubes
  • Label each test tube with Parafilm so that you don’t mix up the liquids
  • When you are ready, put the coins in the test tubes.
  • Leave them in the test tubes overnight.
  • After a night, take the coins out of the test tubes and take a picture of what they look like now.
  • Note the changes from when they first went in to when you took them out.

    • ]]>     2018-05-01 07:46:57 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256777769     Conclusion 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794157
  • My hypothesis was right, the coins came out shiny.
  • This is because certain liquids contain acid (vinegar = acetic acid, Coca Cola = Phosphoric acid) and the rust on the coins contains copper oxide
  • The acid reacted with the oxide and “cleaned” the coins.
  • The milk and water had no impact whatsoever on the coins.

    • ]]>     2018-05-01 09:54:22 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794157     Sources of error 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794207
  •  I had no Coca Cola with me on the day of the experiment, so I had to do it a week later when I had some and when I had time.
  • I had no spare time or classes during the week to complete the experiment, so I was delayed a week when finishing the experiment.
    • ]]>     2018-05-01 09:54:49 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794207     Refinements 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794256
  •  I could try and use more liquids that contains acids or bases, even ones who contain little acid or base. As the milk and water had no impact on the coins
  • I could record the pH of the liquids before using them.
    • ]]>     2018-05-01 09:55:13 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794256     Extension 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794290
  •  I could use 10c or 20c coins, which are gold coloured, that are old and dirty, to see if there is a similar or the same effect.
    • ]]>     2018-05-01 09:55:29 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/256794290     Variables 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201065
  • I used a different liquid for each coin

    • ]]>     2018-05-09 09:19:29 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201065     Constant 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201116
  • I measured 30 cm3 of each liquid to put in the test tube
  • I used 4 5c coins that look similar and are old and dirty

    • ]]>     2018-05-09 09:19:49 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201116     The Beaker, the Measuring Cylinder, the Test Tubes and the Test Tube Holder 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201415 2018-05-09 09:21:18 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201415 The Test Tubes and the Test Tube Holder 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201457 2018-05-09 09:21:36 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201457 Before 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201640 2018-05-09 09:22:46 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201640 After 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201704 (Water, Milk, Vinegar)]]> 2018-05-09 09:23:12 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201704 After 16bodwyer https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201775 (Coca- Cola)]]> 2018-05-09 09:23:38 UTC https://padlet.com/16bodwyer/yfz25cnbgz/wish/259201775