What's the Evidence | science-notebook

Problem:

What are some signs that a chemical reaction has taken place?

Materials:

Procedure:

Download data table from Moodle.

Part 1:

Put a pea-sized pile of sodium carbonate into a 100mL beaker. Record in the data table the appearance of the sodium carbonate.
Observe a dropper containing hydrochloric acid. Record the appearance of the acid.
Make a prediction about how you think the acid and the sodium carbonate will react.
Add about 10 drops of hydrochloric acid to the sodium carbonate. Swirl to mix the contents of the beaker. Record your observations.

Part 2:

Fold up the sides of the aluminum oil square to make a small tray.
Use a spatula to place a pea-sized pile of sugar into the tray.
Carefully describe the appearance of the sugar in your data table.
Predict what you think will happen if you heat the sugar. Record your prediction.
Take the tea candle and your aluminum square with the sugar outside. Carefully light the candle with a match only after being instructed to do so by your teacher.
Use tongs to hold the aluminum tray. Heat the sugar slowly by moving the tray gently back and forth over the flame. Make observations while the sugar is heating.
When you think there is no longer a chemical reaction occurring, blow out the candle.
Allow the tray to cool for a few seconds and set it down. Record your observations of the material left in the tray.

Part 3:

Put about 2 mL of copper sulfate solution in one beaker using a pipette. Caution: Copper sulfate is poisonous and can stain your skin and clothes. Do not touch it or get in in your mouth. Using a 10mL graduated cylinder, measure 2mL of sodium carbonate solution in another beaker. Record the appearance of both liquids.
Write a prediction of what you think will happen when the two solutions are mixed.
Combine the two solutions and record your observations.
Wash your hands.

Data:

Place a screen shot of the table from MS Word in this location.

Problem:

What are some signs that a chemical reaction has taken place?

Materials:

Procedure:

Download data table from Moodle.

Part 1:

Put a pea-sized pile of sodium carbonate into a 100mL beaker. Record in the data table the appearance of the sodium carbonate.
Observe a dropper containing hydrochloric acid. Record the appearance of the acid.
Make a prediction about how you think the acid and the sodium carbonate will react.
Add about 10 drops of hydrochloric acid to the sodium carbonate. Swirl to mix the contents of the beaker. Record your observations.

Part 2:

Fold up the sides of the aluminum oil square to make a small tray.
Use a spatula to place a pea-sized pile of sugar into the tray.
Carefully describe the appearance of the sugar in your data table.
Predict what you think will happen if you heat the sugar. Record your prediction.
Take the tea candle and your aluminum square with the sugar outside. Carefully light the candle with a match only after being instructed to do so by your teacher.
Use tongs to hold the aluminum tray. Heat the sugar slowly by moving the tray gently back and forth over the flame. Make observations while the sugar is heating.
When you think there is no longer a chemical reaction occurring, blow out the candle.
Allow the tray to cool for a few seconds and set it down. Record your observations of the material left in the tray.

Part 3:

Put about 2 mL of copper sulfate solution in one beaker using a pipette. Caution: Copper sulfate is poisonous and can stain your skin and clothes. Do not touch it or get in in your mouth. Using a 10mL graduated cylinder, measure 2mL of sodium carbonate solution in another beaker. Record the appearance of both liquids.
Write a prediction of what you think will happen when the two solutions are mixed.
Combine the two solutions and record your observations.
Wash your hands.

Data:

Place a screen shot of the table from MS Word in this location.

Analysis:

Which of your predictions were accurate?

My Copper Sulfate and Sodium Carbonate Solutions predictions was correct.

What was the biggest surprise?

That the first test became solid.

How did you know when the reaction in Part 1 was over?

When it was solid we knew that it was over.

What was the evidence of a chemical reaction in Part 1?

It started crackling and became dry.

What was the evidence of a chemical reaction in Part 2?

The sugar started to melt.

Was the reaction in Part 2 endothermic or exothermic? Explain.

It was exothermic because it let out heat.

Was the product of the reaction in Part 3 a solid, a liquid, or a gas?

It became a solid.

Conclusion:

(What did you learn from the activity? What are additional questions you have?)

I learned that two liquids can become solid. My question is how?

Conclusion

The mixture turned blue. Why did the mixture turn blue though, how did that happen? The smell was the smell of caramel. It became caramel. :)