Introduction


A reaction is the behaviour of different chemicals as they interact. Colour change, production of heat, gas or light or the formation of precipitates indicate that a reaction has taken place. Reactions can occur at different rates.

The rate of reaction between any substances is determined by many different factors. These factors include concentration, temperature, and any catalysts involved in the reaction. Concentration is the percent ratio of the water compared to the chemical, the lower the percentage the lower the concentration of the chemical involved. Temperature can affect the rate of reaction depending on the extremes. A different temperature will either speed up or slow down the reaction rate of the chemicals involved. The final factor that will be examined, is the presence of catalysts. A Catalyst is a substance that initiates or accelerates a reaction, without actually being a reactant in the reaction.

In the following series of experiments, reaction rates will be measured and conclusions will be drawn. These conclusions will be compared to the circumstances in which the reaction has taken place which will prove and describe the above factors.

Reaction Example: H2 + Cl2 --> 2 HCl
Reaction of H2 + Cl2
Reaction of H2 + Cl2
Reaction
Reaction




Materials


Experiments
Materials: Chemical
Materials: Equipment

Materials: Safety
1 - Temperature
-3 Alka seltzer Tablets
-Hot water
-Cold water
-Water at room temperature

-3 beakers
-1 measuring cup
-1 thermometer
-1 stopwatch
-Safety goggles
2 - Concentration
-Vinegar
-Water
-Baking soda
-6 Beakers
-1 Dropper
-3 Measuring cups
-Measuring spoons
-1 Stopwatch
-3 stirring rods

-Safety goggles
3 - Catalysts
-Manganese Dioxide
-Hydrogen peroxide
-2 test tubes
-2 balloons
-1 stopwatch




-Safety goggles


Experiment 1: Temperature

Procedure

1) Place 50 mL hot water into a beaker

2) Record the temperature

3) Place 1 Alka-Seltzer tablet in the hot water and record how long it takes to completly dissolve

4) Repeat steps 1-3 for room temperature and cold water

5) Record results and compare


Thermometer
Thermometer
Thermometer

Obseravtions

|| WATER TYPE (exact temp.) || TIME FOR COMPLETE DISSOLVE || GENERAL OBSERVATIONS || || Hot || 17.34 sec || Many large bubbles, fizzing sound || || Room temperature || 52.24 sec || Many bubbles, gentle fizzing sound || || Cold || 104.52 sec || Slow, very small bubbles ||

Conclusion: The observations from the experiment show that an Alka-Seltzer tablet dissolved completely after 17.34 seconds in hot water, 52.24 seconds in room temperature water and 104.52 seconds in cold water. In response to higher temperatures, particles begin to move more quickly. Once the particles are moving faster, collisions become more frequent then when the particles were moving more slowly. These collisions between particles occur in smaller amounts of time as they are happening faster and more frequently. Therefore temperature has a direct relationship with the rate of reaction in that the higher the temperature, the faster the reaction takes place. Experiment 2: Concentration Procedure

Obseravtions

Conclusion: Experiment 3: Catalyst

Procedure

Obseravtions

Conclusion





Experiment 2- Concentration Part A: 1) In the first beaker, place a tablespoon of baking soda 2) In the second beaker, mix together 10 mL of vinegar with 5 drops of water 3) Slowly pour the vinegar/water mixture into the beaker filled with baking soda 4) Observe and record the reaction results as well as the time taken for the reaction to occur Part B: 1) In a clean beaker, place a tablespoon of baking soda 2) In a second clean beaker, mix together 5 mL of water with 5mL of vinegar 3) Slowly pour the vinegar/water mixture into the beaker filled with baking soda 4) Observe and record the reaction results as well as the time taken for the reaction to occur Part C: 1) In a clean beaker, place a tablespoon of baking soda 2) In a second clean beaker, mix together 10 mL of water and 5 drops of vinegar 3) Slowly pour the vinegar/water mixture into the braker filled with baking soda 4) Observe and record the reaction results as well as the time taken for the reaction to occur -Compare results from Parts A, B and C external image bakingsodavinegar.jpg vinegar and baking soda Experiment 3: Catalysts Part A: 1) Fill Half of a clean test tube with hydrogen peroxide 2) Place a balloon on the top of the test tube 3) Record results Part B: 1) Fill half of a clean test tube with hydrogen peroxide 2) Add manganese Dioxide and quickly place a balloon on the top of the test tube 3) Record results Compairs results from Part A and B. external image hydrogen_peroxide_structure_400.gifexternal image Manganese-dioxide-sample.jpg manganese dioxide

Safety Precautions

It is important to take the necessary precautions when handling chemicals as they can be very dangerous. Always wear safety goggles, and have any long hair tied back to avoid any accidents and always make sure to wash your hands after an experiment. When using the manganese dioxide and hydrogen peroxide in experiment three, be sure to remain a safe distance away from any open flames as the chemicals can explode. Experiment 2

|| VINEGAR vs. WATER || TIME || GENERAL OBSERVATIONS || || High Concentration Vinegar: 10mL Vinegar 5 drops Water || 23.66 sec || Bubbles formed Fizzing || || 5mL Vinegar 5mL Water || 20.95 sec || Less fizzing Less bubbles More baking soda leftover || || Low Concentration Vinegar: 10mL Water 5 drops Vinegar || 15.7 sec || No more clumps Made one solution No fizzing ||


Experiment 3

|| PRESENCE OF CATALYST || TIME || INFLATION OF BALLOON || GENERAL OBSERVATIONS || || No Catalyst -just 5mL Hydrogen Peroxide || 30 sec || Nothing || Balloon did not fill Nothing happened || || Catalyst -Manganese Dioxide in 5mL Hydrogen Peroxide || 5 sec || Slight inflation of balloon || Balloon went upright when attached to test tube, inflated slightly, then test tube started to get hot || ||^ || 10 sec || Production of heat ||^ ||


Analysis: Experiment 3: Catalysts include chem eqn *One question.....our experiment for the catalyst just proves that there is indeed a catalyst needed in this scenario for a reaction to take place and creat oxygen....it doesn't show whether manganese dioxide is a positive catalyst which speeds up a reaction or a negative catalyst that slows down a reaction.....so what was the point of this experiment? What conclusion can we draw that will relate to the rate of reaction, not just a reaction taking place?? -Adrian help! it won't let me add my graphs from excel WE STILL NEED TO DO: ANY CALCULATIONS, RESULT EXPLANATION AND CONCLUSION, SUGGESTIONS FOR PROJECT MODIFICATION AND FIXING THE MEASUREMENTS IN THE PROCEDURE TO MATCH WHAT WE ACTUALLY DID! This is sude friday so we should get on it and discuss what we should do for our presentation!! The tables I made on microsoft word for observations were a lot prettier than they are on this page so sorry about that -Adrian Yo we also got to change the procedure and Materials cuz we changed it in class We'll talk about it tomorrow (Monday) -Roderick where are the exact temps in the observations??? We hadn't written them down on our obesrevation sheets and unfortunately the only temperatures I remember is the hot water which was around 60deg and then the room temp one was around 24deg.... Im going to do the vinegar-baking soda test again. I think what just happened was that we wrote the times in the wrong spots. The higher concentration should have a faster time. Also, I'm going to calculate the molarity of the concentrations. -Roderick

This page was created by all of the members of this group Emma, Adrian, Roderick, Fraser