Download Lab1_Lab2-1 - chem

Lab Activity #2.1 – States of Matter
Objective: Create a model for each of the 3 states of matter, using your powers of observation.
Procedure:
1. Write a definition for each of the following: solid, liquid, gas.
2. Now use the syringes at your lab station For each substance that is sealed in a syringe, test
the compressibility by pushing on the plunger and observing the decrease in volume for
the substance. Record your findings. (Press syringes according to directions!)
3. Using words and pictures, develop and draw a model which explains the compressibility
differences between a solid, liquid and a gas based on your findings from lab.
4. Give 2 examples of each phase of matter. List at least 3 characteristics that classify a
substance as a solid, as a liquid, or as a gas.
5. Make a sample of oobleck (2 parts corn starch and 1 part water). Investigate its properties
and record your findings. Under what conditions does it act as a liquid? A solid?
Lab Activity #2.2 – Chemical Changes and the Nature of Matter
Objectives:
To identify when a chemical reaction takes place based on observations.
To record observations and interpretations using words and pictures.
To become familiar with how chemicals react.
Lead (II) nitrate [Pb(NO3)2] and potassium iodide [KI] are the chemicals used.
Procedure:
1.
2.
3.
4.
Cover the bottom of the petri dish with DI water. From this moment on do not move
or shake the dish. Using the dropper bottles, simultaneously add 6 drops of lead (II)
nitrate solution and 6 drops of potassium iodide solution on opposite sides of the
petri dish. Wait at least 5 minutes before proceeding to step 2.
In another petri dish, repeat step 1 but instead of adding both chemicals at the same
time, add the potassium iodide solution five minutes after you add the lead (II)
nitrate solution.
In a 3rd dish, filled with DI water, add a few crystals of solid lead nitrate at one end
and a few crystals of solid potassium iodide at the other. Record your observations.
Dispose of all solutions as instructed by your teacher.
Questions (Answer the following in your journal):
1. How were the results for each petri dish different? Similar?
2. What interpretations can you make about the behavior of the substances in this activity?
Record in words and pictures. Label your drawings! They are important!
3. What is a chemical solution and how do you think it is made?
Lab Activity #2.3: Chemical Mystery
Objective: To explain how the chemical reaction you see occurred.
Procedure:
1.
2.
Place 2 drops of bromthymol blue (BTB) at one end of a dry Petri dish.
Place 1 drop of hydrochloric acid (HCl) and 1 drop sodium hydrogen sulfate
(NaHSO4) TOGETHER to make 1 big drop at the other end of the Petri dish.
3.
QUICKLY place the lid on the Petri dish and observe.
Questions (Answer the following in your journal):
1.
Describe the changes you saw in the BTB. Drawings are great!
2.
EXPLAIN the reason for the changes you saw in the BTB.