Lab Report
Jack Parks
2/24/14
Lab report
Mr. Sterling
7th Grade science
Question: what happens when soap is added to hard water
In certain parts of the country, minerals like calcium, iron, or magnesium are
naturally dissolved in water. Water that has minerals dissolved in it is called hard
water. These minerals can combine with soap to create soap scum. In this lab we
will make hard water and see how it reacts with soap
Background Info:
Physical change is when a substance changes into another form but does
not gain, lose, or change any proprieties. An example of this is pop corn
seed popping into pop corn. It still is a seed it just became more eatable.
When an object is subject to chemical change it does change its
proprieties and it form. A few examples of chemical change are ice
melting into water and metal rusting. When some is subject to chemical
change unlike physical change needs to be separated by chemical means
if it’s to be changed back.
There are many proprieties to a substance. Some proprieties are volume,
mass, color, and luster. If any of these are changed in a substance then it
is a chemical change. For example when ice melts it loses volume. To
form a precipitate you need to put two substances together and form a
new substance that will not dissolve. An example of this is if you mix
together vinegar and milk to form a type of glue. A solution is two
things mixed together. In our hypotheses we predicted if the mixture will
react to the soap and if it will form a solution.
Hypothesis:
If we combine soap with regular water it will dissolve the soap
I think this will happen because soap reacts to water by melting
If we combine soap with water it will foam up
I think this because the same chemicals that dissolve the metals will react to the
soap
Procedure:
1. Label three cups soap, water, and hard water
2. Place three table spoons o water into the soap cup and two tablespoons
into water and hard water
3. Put ivory soap onto paper and scrape of flakes with a plastic spoon or
popsicle sticks
4. Add one tablespoon of flakes to the water in the soap cup and stir till it
turns white
5. Make ‘hard water’ by adding two teaspoons of Epsom salt to the water in
the hard water cup and stir till no more salt will dissolve
6. Use a dropper to pick up soap solution from the soap cup. Then carefully
squirt several droppers full of the solution into a teaspoon until it is full
7. Then pour this teaspoon into the water cup and repeat step 6 again and
also put it into the water cup
8. Using the method in steps 1 and 2 add two teaspoons of the soap
solution to the hard water
9. Look at the cup’s from the top and sides and record your observations at
the top of the following page
Observations:
When we had soap in regular water it looked just like regular water but a little
murkier. But when it was in hard water it was chunky and white. When we blew
bubbles in the water many bubbles but not the hard water.
Analyze Results:
The soap scum did dissolve as well in water as in the soap
The scum didn’t bubble in water as well as soap
All we did was make a mixture and did not make something totally new
There was no chemical reaction when the soap was added to the hard water
I believe that what happened was a physical change
Drawing conclusions:
My first hypothesis was correct because when I mixed the soap with water I
found it did dissolve and became invisible
My second hypothesis was incorrect because when I mixed soap with hard water I
found it didn’t dissolve and became chunky
The best explanation for my results is partially correct because my first
hypotheses was correct but my second was not