Chemical Reactions Introduction

As an introduction to chemical reactions you will be researching, using either the internet or your textbook, concepts related to reactions and chemical equations. During the second part of this introduction you will be using a computer simulation to look at several chemical reactions. Answer all of the questions and write your observations and chemical reactions on a separate piece of paper. Please do not write on this paper.

Part I: Characteristics of reactions

  1. Describe the parts of a chemical equation. What are three things that would show a chemical reaction has taken place in an experiment?
  2. How are chemical reactions abbreviated in place of words?
  3. What is the arrow in a chemical equation used to indicate about the reaction?
  4. What is a diatomic molecule? List the seven elements that are diatomic when found by themselves.
  5. Some chemical reactions involve energy. How is the energy of a reaction indicated in a chemical equation?
  6. Define the terms endothermic and exothermic as they relate to chemical reactions.
  7. Define the law of conservation of mass and the law of conservation of matter.
  8. Why is it necessary to have a balanced chemical equation?

Part II: Computer simulation of reactions

  1. a) To start click on the virtual chemlab icon, you used this program to research Rutherford’s

gold foil experiment.

b)Once in the lab click on the inorganic lab table and enter the stock room. Then place the icon (hand) over the test tubes and drag a test tube to the ring stand. You will then be putting a solution of copper (II) ions, Cu2+, into the test tube by clicking on the Cu2+ bottle from the shelf of chemicals. Click done. Then press the return to lab button where you should see a test tube in the test tube rack.

c)Above the periodic table click on the handle to pull down a screen. With the screen down and the icon over the test tube, you can see what substance(s) is(are) in the test tube. In fact you can write on the test tube label by moving the icon over the test tube label until a pencil appears, double click on the label and type in the ion(s) in the test tube.

  1. a) Move the test tube to the ring stand. At the bottom of the screen are a series of pictures,

find the one that says divide by move the icon over the pictures and click the mouse. You

now have an identical container of the original solution. Make one more test tube of the

same solution the same way.

b)To the tube in the ring stand add some NaOH by clicking on the corresponding labeled bottle on the lab table. Note what happens and write the formulas of the substances that are now in the test tube. Remember to use the screen above the periodic table to see what is in the test tube. Did a chemical reaction occur? How can you tell? Write a chemical equation for the chemical reaction that occurred.

c)If after you combine chemicals the mixture now appears cloudy, that means a precipitate has formed. If this has occurredmove the icon over the bottom picture and click on the centrifuge, other wise skip to part (d). What happened when the centrifuge was used? Once this has been done add NH3 to the substance in the test tube. Record what happened and the formulas of any new chemicals that formed. Write chemical reaction, if any, that occurred.

d)Move the test tube in the ring stand to the trash can which is the red container. Move a new test tube to the ring stand and add NaCl. Record your observations and formulas of any new chemicals that are formed. Write the equation for the reaction, if any that occurred. Dispose of this test tube.

  1. Repeat steps 1b through 2d using Pb2+, K+, and Ba2+. You will have a total of four separate ions you will have tested.