Alka Seltzer Synthesis Lab

4. It would be difficult to measure the concentration of acid in red wine or coca-cola because the colour of the drink is too dark for us to see when the phenolphthalein indicator changes colour. You could overcome this difficulty by using a pH meter.

Our testable question was, what is the effect of different liquids on the dissolving rate of the alka seltzer. To answer this question we dissolved alka seltzer in three different liquids, and recorded the data we found. After testing water three times

In this lab we tested how changing the content of the water affects the speed of the alka seltzer dissolving. My hypothesis was that the tap water would dissolve the tablet fastest, the salt water would be second fastest, and the sugar water would be the slowest. I was correct that the tap water would dissolve the fastest, but I was wrong in that the salt water would dissolve faster than the sugar water. I think that our results came out the way they did because of the amount of sugar and salt we put into the water. When we put the sugar and salt into the beakers, we came up with those measurements on the spot. After the salt and sugar had been added, the salt water was very cloudy, but you could barely tell the tap water from the sugar water.

Introduction: Alka-seltzer contains three active ingredients, aspirin, sodium hydrogen carbonate and citric acid. It is used for headaches, migraines, and cold and flu symptoms. Alka-Seltzer is usually taken when dissolved in a glass of water. When placed in water a series of chemical reactions result into Sodium citrate and Sodium acetylsalicylate. The sodium citrate would act as the antacid for stomach pains, and the sodium acetylsalicylate would act as the pain reliever.

Ever wonder about the chemical makeup of tablets that people take for pain relief? Before a tablet can be successfully made, the limiting and excess reactants must be considered. The limiting reactant will affect the amount of the product that can be made. Another reason why the starting reactants must be determined carefully is to make reduce the amount of the reactant in excess so that reactants are not wasted. This experiment uses an Alka-Seltzer tablet. Alka-Seltzer dissolves in water and is an antacid and a pain reliever1. The Alka-Seltzer tablet has many uses such as relief of headaches, ingestion, heart burns, or even upset stomachs2. The active ingredients in an Alka-Seltzer tablet is aspirin, also known as acetyl-salicylic acid (C8H12O4), citric acid (C6H8O7), and sodium bicarbonate (NaHCO3)2. The aspirin in the Alka-Seltzer tablet helps with pain relief. Because of the acid-base chemistry (Brønsted-Lowry), citric acid and sodium bicarbonate produce O2, which makes the tablet fizz when it is dropped in liquid. The Brønsted-Lowry theory shows how the Brønsted-Lowry acid donates a hydrogen ion while the Brønsted-Lowry base accepts the hydrogen ions3. The remaining NaHCO3 that is in excess post reaction with the citric acid is what is used to neutralize stomach acid which helps relief heart burn2. The problem in

Sodium bicarbonate has a molar mass of 84.0 g/mol. It has a melting point of 50°C and can be an irritant.

The goal of this lab was to determine the amount of grams of sodium bicarbonate (NaHCO3) required to produce enough CO2 gas to completely fill the lab and also how many Alka-Seltzer tablets that would equate to. This was done by collecting CO2 gas by inverting a buret and submerging it under water in order to calculate the volume of CO2 released from a fragment of Alka-Seltzer tablet. The main component of Alka-Seltzer is sodium bicarbonate, used to neutralize excess stomach acid during illness through the following reaction that generates CO2:

In this experiment, the precision of percent by mass of sodium carbonate was decent. It seemed to be consistent, although we seemed to have an outlier in our fifth trial. I believe this was due to human error of adding too much vinegar to this graduated cylinder. The accuracy of our results was decent in comparison to the rest of the class’s data, but our results were on the higher end compared to the averages of the class data, though not too high to be considered

* By using the dropper and measuring cylinder, 7 ml sodium carbonate solution was added to the test tube

The manufacturer results shows that Alka-Seltzer has 1.9 grams per tablet. In the experiment the results are too small compared to the number that is given by the label. In the first run only .0588 grams reacted to the acid. That suggest that the tablet only contains 0.588 grams of sodium bicarbonate which is very different from the manufacturers. The second run gave an even smaller number of gram. In terms of moles only .0007 reacted in the first and third run and only .0006 in the second run. There are many factor that could had alter the amount of moles that reacted to the acid which affected the result in showing that there is a smaller composition of sodium bicarbonate in the tablet than that of the manufacturer’s.

How does the dissolve rate of the Alka-Seltzer tablets change as the temperature of the water changes? The dissolve rate is being affected by the temperature of the water. Temperature is a measure of kinetic energy in molecules (NYU). The higher the temperature, the higher the kinetic energy. Energy is required to create a reaction. Molecules with more energy come into contact with each other more often. The molecules of the reactants have to come into contact with each other, so more energy in molecules result in faster dissolving time.

In this experiment the scientists are looking for how gas production is effected when different sized Alka-Seltzer tablets are put into water. The independent variable is the different sizes while the dependent variable is the amount of gas produced. A constant variable includes the same brand of Alka-Seltzer tablets, the volume of water and same starting temperature. Finally the scientist’s control variable is the first trial testing the whole tablet comparing its reaction time to each new piece.

Alka Seltzer is a medical drug used for pain relief and used for relieving indigestion. For example, if you have a stomachache or some indigestion problems, Alka Seltzer may help neutralize the stomach acidity. Not only that, Alka Seltzer is also used for cleaning household items, such as vases or jewelry. Alka Seltzer contains citric acid and sodium bicarbonate, which makes it dissolve and release carbon dioxide gas when dropped in water. In this experiment, my lab partner, Rebecca, and I are trying to find a way to make Alka Seltzer dissolve faster in water. Rebecca and I both decide that if we increase the temperature of the water or make the water hotter, then the Alka Seltzer will dissolve faster because I know when salt and sugar dissolve in hot water, they dissolve faster. I predict that this same result would apply to this experiment.

The volume of carbon dioxide gas produced from a reaction was measured in order to determine what carbonate sample was used. A gas assembly apparatus was used to capture the gas from a reaction between an unknown carbonate and 6M hydrochloric acid; three trials were performed. The mass of the unknown carbonate was determined, and the reaction occurred in a test tube. The volume of gas produced by the reaction was measured, and the partial pressure of carbon dioxide was calculated after the partial pressure of water vapor was determined using Dalton’s Law of Partial Pressures. The percent mass of carbon dioxide gas was then calculated, and the average mass percent was compared to the table of known carbonates. It was concluded that the unknown carbonate sample used in the reaction was magnesium carbonate.

The soda ash form experiment 3 was obtained. A 250 ml beaker was obtained and rinsed.