Rate of Reaction Lab

By Laura Hospitál on Dec 02, 2015

Students in middle school and high school learn that the rate of a chemical reaction can be affected by concentration, surface area, temperature, and catalysts.  
 
This simple experiment compares the rate of reaction using ground chalk (greater surface area) and whole pieces of chalk (less surface area) when chalk reacts with vinegar.  The expected result is an increased rate of reaction when greater surface area of the chalk is exposed. 
 
This lab also allows students to learn how to use a mortar and pestle to make ground chalk for the experiment.  
 
My students had a blast doing this!
 

Preparation:

Make sure to purchase chalk that is made of calcium carbonate.  DO NOT USE SIDEWALK CHALK as it is not made of calcium carbonate.  Crayola Anti-Dust chalk is normally found at school and educational supply stores and is made of calcium carbonate.
 

Materials

Per Lab group: Make sure to purchase chalk that is made of calcium carbonate.  DO NOT USE SIDEWALK CHALK as it is not made of calcium carbonate.  Crayola Anti-Dust chalk is normally found at school and educational supply stores and is made of calcium carbonate. (Please excuse repetition but this is important.)  

Procedure

Also, please see attached documents including Duxbury files. 
  1. Grind 1 piece of chalk using a mortar and pestle
  2. Leave the 2nd piece of chalk whole
  3. Prepare stopwatch to time the reactions.
  4. Add 100 mL of vinegar to the ground chalk.
  5. Observe the reaction and record observations.
  6. Time the reaction and record.
  7. Add 100 mL to the entire piece of chalk
  8. Observe the reaction and record observations
  9. Time the reaction and record.
  10.  Which piece of chalk produced a faster reaction? – Why do you think this is?
Data and Observations: ____________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________   Conclusion: ________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________

NGSS Standards:

High School PS1.B: Chemical Reactions
Chemical processes, their rates, and whether or not energy is stored or released can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy. (HSPS1-4), (HS-PS1-5)
 
rate of reaction collage
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