Prior Thoughts (2 points)
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What does the term reaction rate mean? The term reaction rate refers to the speed at which a chemical reaction occurs. It measures how quickly reactants are converted into products over a specified period of time.
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Do you think temperature will affect reaction rate? How? Why? Yes, I think temperature will affect reaction rate. Generally, at higher temperatures, particles move faster and collide more frequently with greater energy. This increases the likelihood of successful collisions leading to a reaction, thus speeding up the reaction rate.
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Do you think particle size will affect reaction rate? How? Why? Yes, I believe that particle size will affect reaction rate. Smaller particles have a larger surface area compared to larger chunks, which allows for more collisions between reactant particles. This increased surface area can lead to a higher reaction rate.
Hypothesis (2 points)
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Hypothesis about temperature and reaction rate: If I increase the temperature of the reaction environment, then the reaction rate will increase.
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Hypothesis about particle size/surface area and reaction rate: If I decrease the particle size of a reactant, then the reaction rate will increase.
Variables (4 points)
| Hypothesis | Independent Variable | Dependent Variable | |----------------------------------|-------------------------|-------------------------| | Temperature and reaction rate | Temperature (°C) | Reaction time | | Particle size and reaction rate | Particle size | Reaction time |
Experiment and Data Collection (6 points)
Table A: Cold Water
| Temp. (°C) | Approx Volume (mL) | Reaction Time | Solid | Chunks | Powder | |-------------|---------------------|----------------|-------|--------|--------| | 5 | 50 | 120 sec | N/A | 150 sec| 80 sec |
Table B: Room Temp. Water
| Temp. (°C) | Approx Volume (mL) | Reaction Time | Solid | Chunks | Powder | |-------------|---------------------|----------------|-------|--------|--------| | 22 | 50 | 60 sec | N/A | 80 sec | 50 sec |
Table C: Hot Water
| Temp. (°C) | Approx Volume (mL) | Reaction Time | Solid | Chunks | Powder | |-------------|---------------------|----------------|-------|--------|--------| | 55 | 50 | 30 sec | N/A | 40 sec | 20 sec |
Analyze Your Data and Draw a Conclusion (5 points)
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Conclusion about the relationship between temperature and reaction rate: The data indicates that as the temperature increases, the reaction rate increases. For example, in hot water (55 °C), the average reaction time for the powder was 20 seconds, whereas in cold water (5 °C), it took 80 seconds. This supports the hypothesis that higher temperatures boost reaction rates.
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Conclusion about the relationship between particle size and reaction rate: The data shows that smaller particle sizes lead to faster reaction rates. The reaction time for the powdered reactant at room temperature was 50 seconds, compared to 80 seconds for the chunks. This evidence suggests that reducing particle size increases the rate of the reaction.
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Were your original hypotheses supported? Yes, both hypotheses were supported. The reaction rate increased with higher temperature and decreased particle size.
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Most surprising or interesting thing about this experiment: The most interesting observation was how dramatically the reaction rate changed with temperature. The stark difference in reaction times, such as the 80 seconds in cold water versus 20 seconds in hot water, emphasized just how significant temperature is in influencing reaction rates.
Reflection (5 points)
Part A: In the experiment with the glow sticks, the glow stick placed in hot water will be brighter once it is bent. This is because higher temperatures enhance the chemical reaction that causes the glow, allowing the glow stick to emit more light. The experiment demonstrated that at increased temperatures, reaction rates quicken, which aligns with the data we collected. For instance, the reaction in hot water resulted in significantly faster reaction times compared to cold water in the previous experiments.
Part B: In conclusion, based on the data collected, the hot environment produces a more vibrant glow due to quicker chemical reactions, enhancing brightness.