Hard Water Experiments.

Here is two "science projects" to have fun with. It explains the term "hard water" and interesting facts. (5/07/2007)


After a water softener was installed at home, I had the idea to test if the water is hard or soft after the installation. Water is called "hard" when it have lots of dissolved minerals. Dishwasher soaps have water softeners to improve the cleaning and form bubbles easily. So, here is two experiments using "hard water" (also known as tap water). First, How to sink a paper clip that floats on water? without touching the water, the clip or the cup. (see how to make a paperclip to float on water )


floating paper clip For this experiment, we need:


* Dishwasher soap or any kind of soap to clean dishes.
* A cup.
* paper clips.
* Water.



floating paperclip Here is the trick:


I need to sink the clip without touching it. Nothing should to touch the clip or the cup. The solution is simple: Just lower the density of the water.


add dishwashing soap To lower the density of the water, just add a drop of soap and the paperclip immediately sinks!


As the surface tension was enough to make the paper clip to float, the soap lowers the density of the water and there is not enough surface tension to hold the clip, therefore, it sinks.


Not having fun? here is another experiment with a lot of fun:


material needed For this one, I need:


* A wide dish (plate).
* Water.
* a business card or paper
* Scissors.


cut the business card Put some water on the plate, cut a small triangle from the card.



put some soap on the paper Put a drop of dishwashing soap on the small triangle, it will work as the "motor"


drop detail Here is a drop on the piece of the card. As I did mention before, it will be the motor and it will push the triangle on the water.


Drop the triangle on the water and look how it travels around the plate.


So... what happen here? why the triangle with the dishwasher soap moves on the water?


Again, the soap "softens" the water, makes it changes the density of the water.


As there is a difference of density, the water itself pushes the triangle until the water is completely "soft". Basically, the surface tension is lower on the back and it expands where the surface tension is higher.


If you want to try the experiment, you need to change the water, it works only with "hard water".


Another interesting use of dishwasher soap are bubbles. I will show you interesting experiments with soap bubbles...


... someday.



 < Growing Salt Crystals.Homepage
science Index
Homemade Gramophone (Phonograph)> 


If any information, data, picture or design infringes a copyrighted material, please send me an e-mail asking to remove it along with the supporting data.
Some features may not work with Google Chrome. © 2006-2010 Jose Pino - Powered by JPC Alpha