Investigation Lab
Apply scientific methods to explore chemical concepts.
Learn
Scientific Investigation Skills
- Observation: Notice changes in color, temperature, or state
- Evidence of reactions: Gas production, color change, precipitate, energy change
- Safety: Follow lab safety procedures at all times
- Data collection: Record observations accurately
- Conclusions: Explain results using chemistry concepts
Practice
Question 1: Baking soda and vinegar produce bubbles when mixed. What evidence of a chemical reaction is this?
Answer
Gas production (carbon dioxide bubbles) is evidence of a chemical reaction.
Question 2: Why is it important to record observations during a lab?
Answer
Accurate records allow you to analyze results, identify patterns, and draw valid conclusions from your experiment.
Question 3: A clear solution turns cloudy when two liquids are mixed. What might have formed?
Answer
A precipitate (solid) may have formed, which is evidence of a chemical reaction.
Question 4: What is a control group in an experiment?
Answer
A control group is not exposed to the experimental variable and serves as a baseline for comparison.
Question 5: An experiment tests how temperature affects reaction rate. What is the independent variable?
Answer
Temperature is the independent variable (what you change).
Question 6: During a reaction, the container becomes very cold. What type of reaction is this?
Answer
An endothermic reaction (absorbs heat energy from surroundings).
Question 7: List two safety rules for a chemistry lab.
Answer
Examples: Wear safety goggles, never taste chemicals, tie back long hair, wash hands after handling chemicals.
Question 8: A student claims a reaction occurred but has no evidence. Why is this a problem?
Answer
Scientific claims must be supported by observable evidence. Without evidence, the claim cannot be verified.
Question 9: What is the dependent variable in an experiment?
Answer
The dependent variable is what you measure or observe as a result of changing the independent variable.
Question 10: How can you tell if a physical change occurred versus a chemical change?
Answer
Physical changes can usually be reversed (melting ice), while chemical changes produce new substances and show evidence like gas, color change, or energy release.