the effect of temperature and particle size of the reaction rate of an Alka–Seltzer tablet

Problem

The problem is –

What is the effect of temperature and particle size of the reaction rate of an Alka–Seltzer tablet? This means that we want to know whether the temperature or the size of the tablet would change the amount of time it takes to completely dissolve into the water.

Purpose

I chose this project for many specific reasons. When first deciding what to do for my project, I looked for a topic that interested me. For example, when choosing the project, I was fond of chemistry and decided to choose a topic in that region. When I found my rightful project, I decided to read more about the experiment and I wanted to find the answer to my problem.

Also when choosing the topic, I wanted a topic that was suitable, appropriate and challenging which was combined in the topic of my choice. Therefore, I chose the project that fitted my request.

Research

When you drop Alka – Seltzer tablets in water they produce plenty of bubbles which is carbon dioxide {CO2}. The main ingredients of Alka – Seltzer are aspirin, citric acid and sodium bicarbonate {NaHCO2}. Now when the Alka- Seltzer tablet is placed in water {H2O}, the sodium bicarbonate splits apart and reacts with the hydrogen ions that form citric acid and carbon dioxide. I also found out that molecules had something to do with the project. A molecule is a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction. The French philosopher Rene Descartes founded the molecule in the 1620’s. The molecule is created from two atoms in a covalent bond or a bond when two elements share electrons. The reaction rate of elements is an equation describing the rate on which a chemical reaction occurs. For example, the oxidation of iron under the atmosphere is a slow reaction, which can take many years, but the combustion of butane in a fire is a reaction that takes place in fractions of a second. Sodium bicarbonate is the chemical compound with the formula NaHCO3. It is a salt that has many names such as baking soda. Temperature is the degree of hotness or coldness of a body or environment. It is measured with thermometers and it is a property of matter. Reactants are substances that combine in a chemical reaction. A product is a substance produced during a chemical process and citric acid is a sharp tasting crystalline acid present in the juice of lemons and other sour fruits.

Hypothesis

We predicted that the higher the temperature of the water the quicker the reaction rate because when you put sugar in warm water it dissolves faster. We also thought that the smaller the particle size, the reaction rate would be faster because when things are smaller, they are completed quicker.

Materials

1. Safety goggles or safety glasses

2. 36 Alka–Seltzer tablets

3. Thermometer

4. Syringe

5. Clear wide mouth plastic bottle

6. Aquarium tubing

7. Drill

8. Measuring cup

9. Clear tape

10. Water{hot & cold}

11. Ice

12. Stopwatch with second hand

Variables

While doing the experiment, there were some variables that I kept constant and some I manipulated. Some variables that I kept constant are the amount of tablets I placed in water so that I could have a fair chance; another is the amount of water, which was 8oz, also, the amount of time, which was 10 seconds. There were also some variables that were manipulated. I changed the particle size of some tablets and the temperature was changed.

Procedure

1. Wear safety goggles for this step.

2. Drill a hole in the bottle cap.

3. Squeeze one end of the tubing, press it into the hole and push it through the other side of the cap.

4. Press the other end of the tubing into the syringe.

Ice water test-

1. For ice water, fill the measuring cup until 4oz with ice and place cold water until the 8oz line.

2. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

3. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

4. Place water into bottle with the ice.

5. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

6. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

7. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Warm water test-

1. Try to get the hottest tap water and keep the water running. Then empty the water until it reaches 8oz.

2. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

3. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

4. Place water into bottle with the ice.

5. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

6. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

7. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Half particle size test-

1. Break the two Alka-Seltzer tablets in half.

Ice water

2. For ice water, fill the measuring cup until 4oz with ice and place cold water until the 8oz line.

3. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

4. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

5. Place water into bottle with the ice.

6. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

7. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

8. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Warm water

9. Try to get the hottest tap water and keep the water running. Then empty the water until it reaches 8oz.

10. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

11. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

12. Place water into bottle with the ice.

13. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

14. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

15. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Quarter particle size test-

1. Break the two Alka-Seltzer tablets in quarters.

Ice water

2. For ice water, fill the measuring cup until 4oz with ice and place cold water until the 8oz line.

3. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

4. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

5. Place water into bottle with the ice.

6. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

7. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

8. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Warm water

9. Try to get the hottest tap water and keep the water running. Then empty the water until it reaches 8oz.

10. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

11. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

12. Place water into bottle with the ice.

13. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

14. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

15. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Crushed particle size test-

1. Crush the tablets in the package.

Ice water

2. For ice water, fill the measuring cup until 4oz with ice and place cold water until the 8oz line.

3. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

4. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

5. Place water into bottle with the ice.

6. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

7. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

8. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Warm water

9. Try to get the hottest tap water and keep the water running. Then empty the water until it reaches 8oz.

10. Measure the temperature of the water with the thermometer and wait until red line stays one place. Record data.

11. Have partner ready with stopwatch. When you place tablet in water shout, “start” and start stop watch.

12. Place water into bottle with the ice.

13. Quickly drop two Alka-Seltzer tablets in the bottle and quickly close the cap. Shout, “start” as soon as this is done.

14. For every 10 seconds you partner should shout out “TIME” and then you should record the amount of CO2 in the syringe.

15. Watch closely and when the Alka-Seltzer tablet is dissolve stop checking the time.

Observations, Results, Data

When doing the experiment I saw that when the Alka-Seltzer tablets were dropped into the water, some water was pushed by gas inside the syringe. Also, when the tablets were placed in the water it sounded like a fizz. I noticed that after the reaction and I took out the syringe, water came pouring out of the syringe. I assume this happened because gas was trying to get out. I also found out that a temperature of 430C the two tablets dissolved in less than 30 seconds. I also noticed that the crushed particle size dissolved so fast that the CO2 didn’t have time to reach the syringe. It dissolved in 20 seconds.

Charts, Tables

2 tablets

Water temp.