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How Temperature Affects Reaction Time

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Emilie Brent

on 2 May 2014

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Transcript of How Temperature Affects Reaction Time

Hypothesis
If the temperature increases, then the reaction time will increase. Research indicates that high temperatures speed up reaction times. The cold temperature of a refrigerator slows down the rate at which the food will spoil, or the reaction time.

Purpose
The purpose of this investigation is to test if you can make an Alka-Seltzer fizz faster or slower by changing the temperature of the water. This investigation is important because it would allow us to measure the effect of temperature on the rate of a chemical reaction. This is relative to when scientists are working in a lab, what the temperature needs to be to work with certain chemicals for accurate results as well as safety precautions. Spoiling is a chemical reaction. Knowing this information will tell you what temperature you need to keep your food at before it will spoil.
Variables/Operational Definition
Clark, Jim. “The Effect of Temperature on Reaction Rates.” 2002.

“Classic Endothermic Reaction: Alka-Seltzer & Water.” Copyright 1996- 2013.
November 2002.

Science Buddies. “Carbonation Countdown: The Effect of Temperature on Reaction Time.”
2013 Scientific American, a Division of Nature America, Inc. 29 August 2013.

Sheppard, William. “The Effect of Temperature on Reaction Rates.” 2 June 2009.

Ubeda, Joao. “How Does Temperature Affect the Rate of Chemical Reactions.” eHow
Contributor. Demand Media, Inc. 1999-2013.



Informational Paragraphs
Procedure
1. Set out three 355ml or larger jars.
2. Fill one jar with 250ml (approximately 1 cup) hot tap water, another with 250ml cold tap water with ice and another with 250ml room temperature water, label each jar.
3. Use a washable marker to mark the water level on each jar.
4. Measure the temperature (in degrees Celsius) of whichever jar you are doing, and record it.
5. Proceed to place an Alka-Seltzer tablet in the water.
*NOTE: Have your stopwatch immediately ready when you place the tablet in.
6. Stir the water gently as you are timing.
7. Time the reaction until all the solid white material is gone and the tablet has stopped bubbling, and then press “STOP.”
8. Record the time.
9. Repeat steps 4- 8 for the other two jars.
1. The purpose of this investigation was to found out how temperature affects the reaction time of chemical reactions. This investigation was important because it allows us to identify why food is preserved in freezers and refrigerators.
2. The data collected fully supported the original hypothesis. The temperature did change the reaction time. The cold temperature water of 40°F dissolved the tablet in 2 minutes. While the hot water at 110°F dissolved the tablet in only 39 seconds.
3. The independent variable (temperature) did affect the dependent variable (reaction time). As the independent variable decreased the dependent variable increased. This let me to believe that in order to completely stop a chemical reaction it was to be at the coldest temperature possible.
4. No problems occurred during this investigation
5. No unusual observations were noted.
6. My investigation could be expanded by testing different brands of Alka-Seltzer tables to observe if I would receive different results.
Question
Can you make an Alka-Seltzer fizz faster or slower by changing the temperature of the water?
Works Cited
• Independent Variable: temperature
• Dependent Variable: rate of reaction
• Constant: amount of water, alka seltzer tablets
• Control: cup of water at room temperature
• Operational Definition: The rate of reaction (from the time you put the tablet in the water to when all the solid white material is gone and the tablet has stopped bubbling) will be measured in seconds with a stop watch. The temperature of the water will be measured with a thermometer.

3- Alka- Seltzer tablets
1- Thermometer (273 degrees K- 333 degrees K)
3- Jars (355 mL or larger)
1- Stopwatch
1- Stir stick
- Hot and cold tap water
- Ice
Conclusion
Investigating temperatures with chemical reactions is extremely useful. Each and every household would benefit if they knew what temperature to store their foods at. Based on the results from this experiment, the colder the temperature, the longer it will take for a chemical reaction to occur. We know that spoiling is a chemical reaction. So the colder the temperature the longer we get to keep our food without it spoiling. The purpose of this investigation is to show how and why putting foods in the freezer or refrigerator will preserve them. By knowing this, we would all save an abundance of money every year saving food that we would have thrown out due to spoilage.
Application
As the temperature increases, the rate of reaction increases. Particles can only react when they collide. If you heat a substance, the particles move faster and therefore collide more frequently. That will speed up the rate of reaction.To speed up a reaction, you need to increase the number of the energetic particles, increasing the temperature will do this. Increasing the temperature increases reaction rates because of the large increase in the number of high energy collisions. It is only these collisions that will produce the reaction. Temperature is a measure of the average energy of the molecules in a certain item. As the temperature increases, reactant molecules increase their energy levels, coming closer and closer to the activation energy. Some molecules reach it and undergo the reaction.
Informational Paragraphs
Temperature may affect the reaction process greatly. At higher temperatures the reaction rates increase, and at lower temperatures the reaction rates decrease. For example, if you are cooking something at a high temperature, the product will develop more quickly. If you cook at a very low temperature, you'll be standing at the stove for a much longer time. Temperature is the key to affecting the rate of chemical reactions. As temperature increases, so does the reaction rate. This is the reason why food is stored in the refrigerator. The cold temperature slows down the chemical reactions that lead to its spoiling.
Informational Paragraphs
Alka-Seltzer is a medication that works as a pain reliever and an antacid. The pain reliever used is aspirin and the antacid used is baking soda, or sodium bicarbonate. The tablets also include other ingredients, such as citric acid. To take the tablets, they should be fully dissolved in water, where they undergo a chemical reaction that produces lots of carbon dioxide bubbles. As the tablets dissolve, the sodium bicarbonate splits apart to form sodium and bicarbonate ions. The bicarbonate ions react with hydrogen ions from the citric acid to form carbon dioxide gas (and water). This is how the bubbles are made. How is temperature related to this reaction? For the reaction to occur, the bicarbonate ions must come into contact with the hydrogen ions in just the right way. The probability of the bicarbonate and hydrogen ions doing this is affected by temperature. The higher the temperature, the faster the molecules move; the lower the temperature, the slower they move.
How Temperature Affects Reaction Time
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