Drop one tablet into a cup of water and leave it in your closed refrigerator for around 30 minutes. If any food smells linger, wipe down the inside with another tablet dissolved in a cup of warm water to leave everything odor-free. Instead of overnight soaking or using awkward bottle brushes, a couple of Alka-Seltzer tablets will make the job hassle-free!
Drop two tablets into the container, then add hot water. Swish the solution around until the tablets are dissolved, then leave it to stand for an hour. When you rinse it out, your container will be spotless! Alka-Seltzer can save them from the trash! Fill your container with hot water and add one or two tablets, depending on the size of the container.
When the fizzing stops, let them sit for 30 minutes, and your containers will be as good as new. Jewelry can be very tricky to clean.
If you use the wrong product, you can tarnish or mark your favorite pieces, and may need a professional to put right. Simply drop two tablets in a bowl of warm water, then let your jewelry soak for 20 minutes. Most coffee makers need to be descaled now and again, but many descaling tablets contain very harsh chemicals.
Fill the water chamber of your coffee maker then drop in three tablets. Wait for the tablets to dissolve, then run a brew cycle or descaling cycle if you have one. The combination of citric acid and sodium bicarbonate will gently remove any scale from the internal components. Run another cycle with clean water before brewing your next pot of coffee. Most reactions proceed faster as the temperature increases. Is the same true for dropping an Alka-Seltzer tablet into water? Indeed it is!!
Depending on the temperature of the water, the tablet will stay on the bottom of the container until the reaction is finished very cold water , or float on top of the water through-out the entire reaction warm water. At a temperature in between the two extremes, the tablet will start off on the bottom of the container, then as its mass decreases, gradually move to the surface of the water.
Crushing the tablet into a fine powder can also be used to illustrate the effect of surface area on the rate of a reaction. A much safer although not as spectacular demonstration than blowing flour into a Bunsen Burner flame!! Some students may initially expect that exothermic reactions should proceed much faster than endothermic reactions, but this is clearly not the case. The exothermic conversion of gasoline to the combustion products CO 2 and H 2 O is extremely rapid, but the reaction takes place only after the gasoline has been ignited.
We can classify gasoline as being thermodynamically unstable relative to the products of combustion exothermic process , but kinetically stable reaction is very slow in the absence of a spark. The rate at which a reaction takes place is a function of the height of the energy barrier between reactant and product. This barrier is known as the activation energy E a and the reactant molecules must collide with sufficient energy and the correct orientation with respect to each other to surpass the barrier.
Increasing the concentration of the reactants will result in a greater number of collisions and therefore a faster rate of reaction. Raising the temperature will also lead to a greater number of collisions and therefore a faster rate of reaction. The rate of any reaction involving a substance X can be written as:. The reaction in this activity involves using sodium bicarbonate and citric acid to produce water and carbon dioxide. The tablets contain sodium bicarbonate NaHCO 3 and citric acid.
Once in solution, the two chemicals can then react according to the reaction listed above. The chances of this happening are better when the tablet is crushed into more pieces since the molecules have more opportunities to collide and when the temperature is higher, since the molecules are moving faster.
In this activity, students will experiment with the reaction between Alka Seltzer tablets and water in different conditions. By changing temperature and the surface area available for reaction, students will begin to see what factors chemical engineers can control to get the desired result. 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. 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. Stir the ice cubes in the jar for about a minute so that the temperature evens out. Right before you start the activity use a spoon to remove the cubes. Be careful when handling the hot water. Time how long it takes for the tablet to disappear. You may want to have a helper time the reaction. How long does it take the tablet to disappear? How vigorous are the bubbles?
Again time how long it takes the tablet to disappear. How long does it take the tablet to disappear in the colder water? What temperature change is required to increase the reaction time by a factor of two make it as twice as fast? What about decreasing the reaction time by a factor of two? If there is a greater surface area that is, a tablet is broken up into more pieces to expose more surface , does the same amount of tablet result in the reaction happening faster or slower?
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