The Conservation of Mass

Looks like I need to back track a little, since I apparently have skipped a few lessons.

Module 3 of Exploring Creation with Chemistry – The Conservation of Mass


All that means is matter cannot be created or destroyed; it can only change forms.

In a nut shell, when matter goes through a wiz-bang change the total mass remains the same. Ta-dah!  Still don’t get it?  Ok.

Get a pair of funky colored goggles and neon yellow rubber gloves.  Must haves for all chemistry labs.   Seriously.


Obtain items for exp. 3.1: beakers, watch glass, Lye (we used Drano – washes your troubles down the drain), vinegar, water, pot, purple cabbage, stove, mass scale, stirring rod, etc..  In this experiment we boiled cabbage to get the color out and into the water.  Now we are trying to figure out if the mass of matter is the same before and after it goes through any kind of change.  To do that, we have to measure everything.

We measure the beaker, the lye, the watch glass, the everything…  Here you see my pink student measuring her beaker in her mass scale.  Sorry, I don’t have any measurements to give, because I no longer have their lab write-ups and can’t remember what the weights were.


While the cabbage is boiling  you stop, put your finger on your nose and think about the experiment and where it is going.


Measure out a specific amount of the Lye and place it on the watch glass.   Then have this conversation with one of your students?

  • Student: Mrs. Goodrich, what happens if you get Lye on your fingers?
  • Me:  It burns your skin.
  • Student:  Can I touch it?
  • Me:  No.
  • Student:  Uh, I think I got some on my hands because they are burning a little bit.  Can I go wash my hands?
  • Me:  Sure.  I also got some on my hands.


Here some of the cabbage water is in the beaker with some vinegar.  You can see just a little bit of pink at the bottom of the beaker in the mass scale.  Vinegar (acid) turns the anthocyanins pink.


Next step is to tip the watch glass and pour the Lye into the pink liquid.  Lye is a base and neutralizes the vinegar and turns it into a lovely shade of yellow snot.  I hate the word snot, but that is what the students called it.



So, we had vinegar, Lye, and water with cabbage coloring in it.  All was measured. Let’s say it measured XX grams.  It was then mixed all together causing chemical changes to occur and the whole thing was measured again.  The mass was XX grams.  Ta-dah!

Matter cannot be created or destroyed; it can only change forms.

One response to “The Conservation of Mass

  1. Soooo, let me guess. The student that had to go wash was Rachel! She just had to touch it! LOL! Loving Chemistry through you and your awesome students!

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