Laboratory work

 

Temperature and the Rate of Chemical Reactions

 

Purpose: The purpose of this lab is for students to investigate the effect of temperature on the rate of a chemical reaction.

For this lab, we are going to be taking some qualitative data. Qualitative data describes a quality of an object or event. You may have been asked in a survey to select a number that described how well you liked a particular item; that is an example of qualitative data. In this lab, since we can’t measure the brightness of a glow stick, we are going to rank how bright it is with “1” being brightest and “3” being the dimmest. We are also going to rank how quickly the glow stick reached its maximum brightness with “1” being the quickest ad “3” being the slowest.

 

Materials:

·         Three (3) glass beakers:

o   Fill Beaker A with 200mL of cold water

o   Fill Beaker B 200mL of room temperature water

o   Fill Beaker C with 200mL of hot water.

·         Three glow sticks that are the same size, brand, and color.

·         Thermometer

 

Procedure:

1.      Record the water temperature of each beaker in the table below.

2.      If your glow sticks are in a package, remove them from the package, but do not break them yet!

3.      Once everyone has recorded the water temperature of the beakers, the teacher will turn out the lights.

4.      Once the lights are out, break the three glow sticks at the same time and immediately place one glow stick in each cup.

5.      Observe how bright each glow stick is and how quickly it reached maximum brightness.

6.      Rank the glow sticks based on their brightness and how quickly they reach maximum brightness and record in Table 1 below:

 

Table 1:

Beaker

 

Water Temperature,

°C

Brightness (“1” = Brightest, “3” = Dimmest)

 

How quickly glow stick reached maximum “glow” (“1” = Quickest, “3” Slowest)

A

 

 

 

 

B

 

 

 

 

C

 

 

 

 

 

Questions:

1.      Which beaker contained the brightest glow stick?

2.      What was the water temperature in that beaker?

3.       Which beaker contained the glow stick that reached maximum brightness first?

4.      What was the water temperature in that beaker?

5.      How does the water temperature affect the rate of the chemical reaction occurring in a glow stick? Explain this result using your knowledge of the Kinetic Molecular Theory of Heat.

6.      What evidence do you have that a chemical reaction took place?