Tuesday, October 26, 2010

Chemistry Experiments You Can Do at Home

I have found a web-site which is interesting. http://chemistry.about.com/od/homeexperiments/Chemistry_Experiments_You_Can_Do_at_Home.htm There are some do-it-at-home chemistry experiments. Some are for home schooling, some are for fun, some involve cooking, and some are ill-advised. Check it out and you can try to do it at home. Don't worry if you don't have a chemistry lab because the materials that use are those common household chemicals and other materials found around the house.

Here are some examples of experiment that I take from the web-site.

(1) Make slime


There are lots of recipes for slime. Since most recipes are easy, look for one using ingredients you have on hand.


Difficulty: Easy

Time Required: 15 mins

Here's How:

1.Pour the glue into the jar. If you have a big bottle of glue, you want 4 oz or 1/2 cup of glue.

2.Fill the empty glue bottle with water and stir it into the glue (or add 1/2 cup of water).

3.If desired, add food coloring. Otherwise, the slime will be an opaque white.

4.In a separate, mix one cup (240 ml) of water into the bowl and add 1 teaspoon (5 ml) of borax powder.

5.Slowly stir the glue mixture into the bowl of borax solution.

6.Place the slime that forms into your hands and knead until it feels dry. (Don't worry about the excess water remaining in the bowl.)

7.The more the slime is played with, the firmer and less sticky it will become.

8.Have fun!

9.Store your slime in a zip-lock bag in the fridge (otherwise it will develop mold).

Tips:

1.Use white glue, such as Elmer's brand. Most 'school glues' do not have the correct composition.

2.Don't eat the slime - it isn't especially toxic, but not good for you either!

3.Slime cleans up pretty easily. Remove dried slime after soaking with water.

4.I've got step-by-step video instructions if you would like to see this project in action plus I made a YouTube video of the slime showing what you will get if you use glue gel rather than white glue. Either type of glue works well.

What You Need:

•borax powder

•water

•4 ounce (120 ml) glue (e.g., Elmer's white glue)

•teaspoon

•bowl

•jar or measuring cup

•food coloring (optional)

•measuring cup

(2) Borax snowflake

 

Do real snowflakes melt too quickly? Grow a borax crystal snowflake, color it blue if you like, and enjoy the sparkle all year long!


Difficulty: Average

Time Required: Overnight

Here's How:

1.The first step of making borax crystal snowflakes is to make the snowflake shape. Cut a pipe cleaner into three equal sections.

2.Twist the sections together at their centers to form a six-sided snowflake shape. Don't worry if an end isn't even, just trim to get the desired shape. The snowflake should fit inside the jar.

3.Tie the string to the end of one of the snowflake arms. Tie the other end of the string to the pencil. You want the length to be such that the pencil hangs the snowflake into the jar.

4.Fill the widemouth pint jar with boiling water.

5.Add borax one tablespoon at a time to the boiling water, stirring to dissolve after each addition. The amount used is 3 tablespoons borax per cup of water. It is okay if some undissolved borax settles to the bottom of the jar.

6.If desired, you may tint the mixture with food color.

7.Hang the pipe cleaner snowflake into the jar so that the pencil rests on top of the jar and the snowflake is completely covered with liquid and hangs freely (not touching the bottom of the jar).

8.Allow the jar to sit in an undisturbed location overnight.

9.Look at the pretty crystals!!! You can hang your snowflake as a decoration or in a window to catch the sunlight :-)

Tips:

1.Borax is available at grocery stores in the laundry soap section, such as 20 Mule Team Borax Laundry Booster. Do not use Boraxo soap.

2.Because boiling water is used and because borax isn't intended for eating, adult supervision is recommended for this project.

3.If you can't find borax, you can use sugar or salt (may take longer to grow the crystals, so be patient). Add sugar or salt to the boiling water until it stops dissolving. Ideally you want no crystals at the bottom of the jar.

What You Need:

•string

•wide mouth jar (pint)

•white pipe cleaners

•borax (see tips)

•pencil

•boiling water

•blue food coloring (opt.)

•scissors



(3) Mentos and diet soda fountain
 

Chemical volcanos are classic projects for science fairs and chemistry demonstrations. The mentos and diet soda volcano is similar to the baking soda volcano, except the eruption is really powerful, capable of producing jets of soda several feet high. It's messy, so you might want to do this project outdoors or in a bathroom. It's also non-toxic, so kids can do this project.

Difficulty: Easy
Time Required: chemical volcano takes a few minutes to set up and erupts for a few seconds

Here's How:

1.First, gather your supplies. You can substitute another candy for the Mentos, such as M&Ms or Skittles, but ideally you want candies that stack into a neat column with minimal space between them, have a chalky consistency, and barely fit through the mouth of a 2-liter bottle.

2.Similarly, you could substitute normal soda for diet soda. The project will work just as well, but the resulting eruption will be sticky. Whatever you use, the beverage has to be carbonated!

3.First, you need to stack the candies. The easiest way to do this is to stack them in a test tube narrow enough to form a single column. Otherwise, you can roll a sheet of paper into a tube just barely wide enough for a stack of candies.

4.Place an index card over the opening of the test tube or end of the paper tube to hold the candies in the container. Invert the test tube.

5.Open your full 2-liter bottle of diet soda. The eruption happens very quickly, so set things up: you want the open bottle - index card - roll of candies so that as soon as you remove the index card, the candies will drop smoothly into the bottle.

6.When you're ready, do it! You can repeat the eruption with the same bottle and another stack of candies. Have fun!

What You Need:

•roll of mentos candies

•2-liter bottle of diet soda

•index card

•test tube or sheet of paper

•a mop for cleanup

(4) Invisible ink




This smiley face was made with invisible ink. The face became visible when the paper was heated.

Difficulty: Easy

Time Required: A Few Minutes

Here's How:

1.There are at least two methods to use baking soda as an invisible ink. Mix equal parts water and baking soda.

2.Use a cotton swab, toothpick, or paintbrush to write a message onto white paper, using the baking soda solution as 'ink'.

3.Allow the ink to dry.

4.One way to read the message is to hold the paper up to a heat source, such as a light bulb. The baking soda will cause the writing in the paper to turn brown.

5.A second method to read the message is to paint over the paper with purple grape juice. The message will appear in a different color.

Tips:

1.If you are using the heating method, avoid igniting the paper - don't use a halogen bulb.

2.Baking soda and grape juice react with each other in an acid-base reaction, producing a color change in the paper.

3.The baking soda mixture can also be used more diluted, with one part baking soda to two parts water.

4.Grape juice concentrate results in a more visible color change than regular grape juice.

What You Need:

•Baking Soda

•Paper

•Water

•Light Bulb (heat source)

•Paintbrush or Swab

•Measuring Cup

•Purple Grape Juice (opt.)




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