Chapter 6: Compounds and Elements

Exp. 6. 2 The Decomposition of Water

Exp. 6.2 Equipment


Data and Observations
    Qualitative observations during electrolysis
    Quantitative observations
          Data table

Conclusion statement

        -Respond to the purpose based on the data collected.
             - "Water, a pure substance, was separated into two simpler..."
Discussion
1. What was produced in each test tube and what observations led to these conclusions?
2. Define a compound.
3.
Describe why water is a compound and not a mixture. Think about what you know about mixtures.
      Hints- Can the compound be recreated by simply mixing the substances together?
4. Do the substances making up water have the same or different properties as water? Describe
     some characteristic properties of each to support your response.

Sources of Error

1. Describe an error that could have resulted in a decreased amount of hydrogen collected.
2. How would this have affected the calculated volume ratio of hydrogen to oxygen?

           



Exp. 6. 4 The Synthesis of Zinc Chloride
Title, date and partner's name
Purpose:

Data and Observations

    Qualitative observations
    Prtinted data table. You can resize it on Google Docs to fit.

Conclusion statement
        -Respond to the purposes based on the data collected.
             - "When zinc metal reacts with hydrochloric acid...."

Discussion  Respond in complete sentences using part of the question. Skip a space after your response for each question.
    1. What should have been the ratio of the mass of zinc metal reacted to the mass of chlorine reacted?
    2. If the reaction was completed again and 10 grams of zinc was found to have reacted, how much
        chlorine would have reacted with the zinc?
    3. If the reaction was completed and 30 grams of zinc chloride was found to have been produced, how
        much zinc would have reacted?
    4. All groups used different amounts of zinc. Should this have affected the ratio calculated? Explain.
    5. Zinc and hydrochloric acid were the reactants in this experiment.
            a. If all the zinc used reacted, which of the reactants was in excess in the test tube?
            b. If there was zinc leftover, which of the reactants was in excess in the test tube?  

Sources of Error
    1. Say a group did not pour ALL the liquid from the test tube into the evaporating dish.
            a. How would this affect the mass of zinc chloride that would be calculated?
            b. How would this have affected the ratio of zinc to chlorine reacted?
    2. Say a group did not dry off the unreacted zinc very well.
           
a. How would this affect the mass of zinc reacted that would be calculated?
            b. How would this have affected the ratio of zinc to chlorine reacted?


The Copper Triple Crown
Exp. 6.6 A Reaction with Copper
Title, date and partner's name
Purpose:
To investigate... (or determine...)

Data and Observations
    Qualitative observations
    Quantitative observations
Data table   
Blue Dot Questions
Conclusion statement

        -Respond to the purpose based on your observations.

Exp. 6.7 The Separation of a Mixture of Copper Oxide and Copper
Title, date and partner's name
Purpose:
To investigate... (or determine...)

Data and Observations
    Qualitative observations- organized!
Blue Dot Questions
Conclusion statement

        -Respond to the purpose based on your observations. Be specific.

Exp. 6.9 Precipitating Copper
Title, date and partner's name
Purpose:
To investigate... (or determine...)

Data and Observations
    Qualitative observations- organized!
Blue Dot Questions
Conclusion statement

        -Respond to the purpose based on your observations. Be specific.

The Copper Triple Crown Discussion Questions
Respond in complete sentences using part of the question. Skip a space after your response for each question.
Some good terms to use correctly include: element, compound, subtance, mixture, react

Exp. 6.6
        1. What was the purpose of experiment 6.6?
2. What color was the copper powder before heating?
3. What color was the sample after heating?
4. Was there a mass change?
5. Why did the sample gain mass? Where did the new mass come from?
6. Was a new substance produced? Describe at least two lines of evidence to support your response.

Exp. 6.7
1. What was the purpose of experiment 6.7?
2.
Was the black solid resulting from experiment 6.6 a mixture?
3. What solid was left behind in the test tube after the dark solution was poured out into another test tube?
4. Was the reaction of copper being heated in the presence of oxygen a complete or incomplete reaction? Why?
5. According to the textbook, which substance "dissolved" in the hydrochloric acid?
6. What qualitative observation was made indicating that a chemical reaction took place when the black
       solid was placed in the hydrochloric acid?

Exp. 6.9
1. What was the purpose of experiment 6.9?
2. Referring to class notes, what substance is in the dark solution? Is this an element or compound?
3. What substance was recovered by adding the zinc to the dark solution? Is this an element or compound?
4. What term is used to describe the process of this substance "reappearing"?
5.
What happened to the zinc?
6. Describe the differences between a sample of:   a. copper (Cu)     
                                                                         b. copper oxide (CuO)
                                                                         c. copper oxide (CuO) and copper (Cu)
                                                                        








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