Course Chemistry
Standard: 4, Objective 1
Title: How do you know when a chemical reaction has occurred?
Description: Simple Inquiry lab to introduce chemical reactions.
Materials Needed: dH2O, 0.1M Ammonia, Universal Indicator
Time Needed: 15-20 minutes
Teacher Procedures:
1. Hook activity: Have the students brain storm what are different types of evidence of chemical reactions.
2. have students conduct lab investigation.
Scoring Rubric or answer key:
1. The color change is blue to red, then orange, then yellow, then green. The temp. change is ~2 degrees
2. Yes, a gas was produced. The contents foamed
3. Each of the characteristics of the reaction is evidence of a chemical change, therefore, a chemical change is observed.
Student Page
Title: How do you know when a chemical reaction has occurred?
Introduction: What evidence is there that a chemical reaction occurs? How would you know if chemistry was going on in the container next to you?
Prediction/Hypothesis
If ______,
[state hypothesis]
Then by changing ______and measuring
[INDEPENDENT VARIABLE]
______, I predict that
[DEPENDENT VARIABLE]
______.
[Prediction of results. Be specific. Do not simply state that there will be an effect]
Because ______
______.
[Scientific phenomenon to support your prediction. Cite evidence from your textbook.]
Procedures:
1. Measure 10ml of distilled water in a 25ml graduated cylinder, and pour it into a 100ml beaker. Using a pipette, add one drop of 0.1 M ammonia to the water.
2. Stir 15 drops of universal indicator into the solution with a stirring rod. Observe the solution’s color. Measure its temperature with a thermometer.
3. Drop a piece of effervescent tablet into the solution. Observe what happens. Record your observations, including any temperature change.
Data/Observations:
Analysis
1. Describe and changes in the color or temperature of the solution.
2. Was a gas produced? If so, what did you observe to support this?
3. Did a physical or chemical change occur? Explain.
Conclusion: