4 October Science 8 Beginning Chemical Reactions

Are you watching the moon and recording your observations? This is an important time to watch.

In the next few sessions, we will embark on exploration of chemical reactions. These investigations will yield observations to add to your repertoire. Our discussions will develop the idea that the behavior and properties of matter at the scale we observe can be explained by the behavior and properties of atoms and molecules. This grand explanation is called The Atomic-Molecular Theory of Matter. When consideration of energy is included the explanation is called The Kinetic-Molecular Theory of Matter.

On Friday, when we have a 1-8 day, we will have a lottery to select topics for our final unit of the year, Human Impact on the Earth. You are being assigned these topics at this time so that you can build a base of knowledge. You will need to begin collecting resources to build your familiarity and expertise in the topic area. More on Friday. Before WOW we will devote some time to preparing for the River–a preview of our unit Earth Cycles/Earth Systems.

Reaction 1.

Work with a partner that you have not worked with before, make a 50 ml solution of magnesium sulfate (Epsom salt) and another 50 ml solution of sodium carbonate (Washing soda). Keep a record of how much of each solute you add–the solutions should not be saturated. Leave no solid undissolved. Find the total mass of the beakers and solutions (as picture below).

Next pour solution 1 into solution 2. Do not spill. Observe what happens and describe in words. Take pictures. Measure the mass after mixing. Be sure to keep both beakers on the balance.

Share your data on the class spreadsheet: https://docs.google.com/a/aes.ac.in/spreadsheets/d/1V5y4RdyVXmki565eVOHY-iOgfw_zY0L9tA1sFFcxzqQ/edit?usp=sharing

Here is a description of the reaction in words:

magnesium sulfate + sodium carbonate¬† —-> magnesium carbonate + sodium sulfate

Reaction 2.

Put 5 grams of sodium hydrogen carbonate (baking soda) in a small flask. Put 100 grams of vinegar (5% acetic acid) in a beaker. Find the miss of the flask and baking soda, the beaker and vinegar, AND a dropper as pictured. Next add drops of vinegar to the flask. Observe what happens. Describe in words. Take pictures. Continue adding until the baking soda has disappeared and no more reaction is apparent. Be very careful no to spill any material. Add the vinegar slowly so no material bubbles or splashes out of the flask. Find the mass at the end of the reaction.

Enter your results in the class spreadsheet: https://docs.google.com/a/aes.ac.in/spreadsheets/d/1FPUcINAnYp8lzIQGBFd4dMElVeuZnXBipljpH9gRzgA/edit?usp=sharing

A description of the reaction:

Sodium hydrogen carbonate + acetic acid —>Sodium acetate + water + carbon dioxide

Be sure to record your observations, thoughts, and questions. Be thorough.

About rfrazier

AES profile = http://aes.ac.in/viewprofile.php?u=6946
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