menu   Home About Me Home freebies My Store  

Search My Blog

Loading...
 photo 3am_AB_f1_zps652b0c0f.png    photo 3am_ab_gplus_zps3ab6fefc.png    photo 3am_ab_pin_zpsbfebd6d2.png    photo 3am_tpt1_zpse91e0740.png   photo 3am_ab_email1_zpsebc98a17.png

Saturday, March 1, 2014

Chemistry Lab: How Big Is A Mole?

Two facts we all know about teaching chemistry:

  • The concept of a "mole" is absolutely crucial to the teaching of our class.
  • Many of our students struggle with this concept every single year.
According to the textbook:  A mole is the quantity of a substance that has a mass in grams equal to its molecular mass and contains Avogadro's number of particles.   I think that many students memorize the definition of a mole, but fail to grasp the concept of a mole.  I want my students to be able to visualize a mole and to have a grasp on the size of a mole of substance.

I just added a new lab to my yearly chemistry curriculum.  It is not really an "experiment" but more of a review and reinforcement of the mole concept. The idea of the activity is very simple:  Students are given ordinary household substances and are asked to determine how many moles are in a teaspoon of the substance.

Purpose: 
  1. To determine the number of molecules and/or atoms in small amounts of everyday substances.
  2. To determine how many moles of chalk it takes to write your name on the board.

Materials:               

  • Balance           
  • Weighing dishes        
  • Plastic spoons
  • Water              
  • Salt (NaCl)                 
  • Sugar (C12H22O11)
  • Chalk              
  • Chalkboard    
I had the students find the mass of a teaspoon of a substance.  From this mass, I had students determine the number of moles of substance, the numbers of molecules of substance, and the number of a particular atom within the substance.  The bottom line is that this activity provides repetitive practice in mole conversions.

I was a little concerned that my "sophisticated" high schoolers would find this activity too elementary.  Wrong!!  They embraced the activity whole-heartedly and came away with a better understanding of the "size" of a mole.

The activity concludes with a student-designed experiment.  I asked my students to design an experiment to determine the number of moles of chalk required to write their name on the chalkboard.  Students had to write the steps of their procedure, construct a data table, and convert their data to moles and molecules.  SO SIMPLE, but my students had a great time with this.  They enjoyed comparing the "size" of their name to that of their classmates.

Click above picture to view this product in my TpT store.

No comments:

Post a Comment