This activity introduces the reaction used for the Alka Seltzer Rockets activity, so it is typically performed before building rockets to understand the nature of the reaction before using it.
Before the experiment, ask students to hypothesize what will make the reaction go the fastest and what makes them think that.
This can be anything, but try to seek answers with specific regard to the variables being changed in this activity.
At the end, collect and present all class data on the board. Highlight discrepancies and the general trend. You must be logged in to post a comment. Skip to content. June 19, June 23, Sid M.
Explanation: Crushing or grinding increases the surface area of the salt that is exposed to the molecules of water. Stirring increases the speed at which the particles of salt come in contact with the water molecules. The solubility of a given solute in a given solvent typically depends on temperature. Many salts show a large increase in solubility with temperature. Some solutes exhibit solubility that is fairly independent of temperature. A few, such as cerium III sulfate, become less soluble in water as temperature increases.
Reduction of the particle size often appears to be the first and easiest way to enhance drug dissolution rate. The solubility of drug is often related to the drug particle size. When particle becomes smaller, drug particles have greater interaction with the solvent and then the solubility is increased 4,5. Rasool A. All solubilities were found to increase in nonlinear fashion as a function of nicotinamide concentration. As nouns the difference between solution and dissolution is that solution is a homogeneous mixture, which may be liquid, gas or solid, formed by dissolving one or more substances while dissolution is the termination of an organized body or legislative assembly, especially a formal dismissal.
How does this affect the reaction? Background Alka-Seltzer is a medication that works as a pain reliever and an antacid. Antacids help neutralize stomach acidity, which can cause heartburn. 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 a weak acid that adds flavor—as well as provides important hydrogen ions, which will come into play as you shall soon see.
To take the tablets, they're fully dissolved in water, where they famously undergo a chemical reaction that produces lots of carbon dioxide bubbles—or fizz. Why is this? 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. Can you guess whether fast-moving molecules or slow-moving ones will speed the reaction time? Add cold tap water to about an inch from the rim. What about decreasing the reaction time by a factor of two? If there is a greater surface area i.
Extra : You could turn this activity into a homemade lava lamp! To do this, you will want to use a tall jar or empty clear plastic 1-liter or 2-liter bottle, fill it with about 2 inches of water, add 5 drops of food coloring, and then fill it at least three-quarters full with vegetable oil.
You could repeat this activity using your homemade lava lamp at a cold and hot temperature. You will also want to use one-quarter of an Alka-Seltzer tablet at a time instead of a whole tablet. How does the bicarbonate reaction look in the homemade lava lamp? Did the Alka-Seltzer tablet dissolve much faster in the hot jar compared to the cold one? Were there a lot more bubbles produced initially in the hot water compared to in the cold water? When the Alka-Seltzer tablet was added to the hot water, the tablet should have quickly dissolved, taking around 20 to 30 seconds to do so, depending on the exact temperature.
In the hot water, the tablet should have more vigorously produced bubbles than in the cold water. The higher the temperature, the faster the molecules move, and the more likely it is that the bicarbonate will contact hydrogen in just the right way for the chemical reaction to occur and produce carbon dioxide bubbles.
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