Physical and Chemical Changes of Matter Pre Lab

Name: ______

Physical and Chemical Changes of Matter Pre Lab

Chemical and Physical Properties

The properties of a substance are those characteristics that are used to identify or describe it. When we say that water is "wet", or that silver is "shiny", we are describing materials in terms of their properties. Properties can be divided into the categories of physical properties and chemical properties. Physical properties are readily observable, like; color, size, luster, or smell. Chemical properties are only observable during a chemical reaction. For example, you might not know if sulfur is combustible unless you tried to burn it.

Pieces of matter undergo various changes all of the time. Some changes, like an increase in temperature, are relatively minor. Other changes, like the combustion of a piece of wood, are fairly drastic. These changes are divided into the categories of Physical and Chemical change. The main factor that distinguishes one category form the other is whether or not a particular change results in the production of a new substance.

Chemical and Physical Changes

Physical changes are those changes that do not result in the production of a new substance. If you melt a block of ice, you still have H2O at the end of the change. If you break a bottle, you still have glass. Painting a piece of wood will not make it stop being wood. Some common examples of physical changes are; melting, freezing, condensing, breaking, crushing, cutting, and bending. Special types of physical changes where any object changes state, such as when water freezes or evaporates, are sometimes called change of state operations.

Chemical changes, or chemical reactions, are changes that result in the production of another substance. When you burn a log in a fireplace, you are carrying out a chemical reaction that releases carbon. When you light your Bunsen burner in lab, you are carrying out a chemical reaction that produces water and carbon dioxide. Common examples of chemical changes that you may be somewhat familiar with are; digestion, respiration, photosynthesis, burning, and decomposition. Bottom line is that there is some type of observable product made from a chemical change. There are many signs that a chemical change has taken place including: a change in temperature, smoke appears, a color changes, a smell appears, a new substance appears…

Questions:

1)  What is a physical property? Give some examples.

2)  What is a chemical property? Give some examples.

3)  What is a physical change? Give some examples.

4)  What is a chemical change? Give some examples.

5)  This reading mentions Chemical/Physical Properties and Chemical/Physical Changes. What is the difference between Properties and Changes?

6)  If you were to mix two substances together, what would you look for to determine if there was either a chemical change or physical change?

7)  List several signs that a chemical change has taken place.

8)  Is a phase of matter change a chemical or physical change? Explain:

Hell’s Kitchen

Lab Task—You will be conducting a series of chemical and physical changes on helpless gummy bears at different stations. Your job is to determine how to best torture a gummy. Good Luck…

Safety—today’s lab is NO JOKE at many of the stations. Goggles MUST BE WORN AT ALL TIMES (so as to avoid changing yourself physically or chemically). Also Note—If the smoke alarm is accidentally set off—Blame Miller. Dispose of all used chemicals into the provided waste beakers.

Station DEMONSTRATION STATION IN FRONT—check back in about a half hour to see changes in gummy.

Station 1: Slash and Smash---This station will require 2 gummies. For the first gummy, put them on the piece of wood and slash them. For the second gummy—go to the freezer in the back room and take a frozen gummy out. You will then bring gummy back to station 1 and smash him with a hammer.

Station 2: Boiling and Sinking! Your hot plate should be on with water already heated up. Place a gummy in the suspended test tube. Take a pipette and add the blue biuret solution to the test tube until the gummy is submerged in solution. Lower the test tube into the hot water and observe. After—remove test tube and place in white waste container.

Station 3: Toxic Bath BE CAREFUL!!! Place one gummy in the test tube. Next, fill water using the squirt bottle into the test tube about 2 fingers worth. Add ONE piece of calcium using the scoopula to the test tube and step back to observe. The solution may spit so watch out. After the reaction…make sure the outside of the test tube is dry and feel the bottom of the test tube. The solution inside is toxic, do not spill. After—remove test tube and place in plastic waste container.

Station 4: Special Chamber!

Station 5: Volcanic Eruption. Place one gummy in test tube. Take one scoopula of sodium bicarbonate and place in test tube with gummy. Add one squirt of acetic acid using the pipette and observe. After—remove test tube and place in plastic waste container.

Station 6: Roaster. Place one gummy in test tube. Turn on gas and light burner using matches and wood splint. Put all burnt stuff in waste container in sink. Lower test tube into the fire, observe! After—remove test tube and place in plastic waste container in sink.

Post Lab Questions:

1.  Which stations were the physical changes and which were the chemical changes?

2.  List several signs that chemical changes had taken place:

3.  Which station was the most gummy torture?!?