Educators' Science and Mathematics Institute Series

Winter Ecology Lesson Plan

Descriptive Title:  Comparing Ionic and Polar Covalent Crystals

Submitted By:  Brian Hugo

Subject and Grade Level:  A.P. Chemistry, 12th Grade

Overview/Purpose:  

Students will prepare several ionic crystals and compare their physical properties with a “preserved snowflake.”

To illustrate how a dipole-dipole intermolecular force (hydrogen bonding) can create a crystal lattice similar in many ways to an ionic lattice

Objectives (Learner Outcomes):

Students will be able to discuss the similarities between ice crystals and ionic crystals using qualitative observations and drawings.

Activities and Procedures:  

     Day 1

Students will prepare slides of ionic crystals to dry overnight. (NaCl, KNO3, CuNO3)

Students will research lattice shapes (packing) for the salts that they prepared (CRC guide)

Students will preserve a snowflake on a slide, either this day or prior, when conditions allow.  (James Benko method)

Students will write a short compare/contrast essay discussing differences and similarities between ionic lattices and covalent (ice) crystals in theory.

Day 2

Students will observe and sketch all crystals using a dissection microscope

Students will write a short conclusion comparing the crystals.  There should be sketches of each crystal included

Closure:

Class will discuss how important hydrogen boding is to all of us.  Why does water boil at such a high temp?  Would we have evolved if the hydrogen bond had not been present in the water molecule?

Assessment Strategies:

Grading the comparison/contrast essays

Grading the conclusion and sketches

Resources:

CRC Guide

Materials:

Salts listed

Microscopes

Materials for preserving snowflakes

Standards Addressed:

Using scientific knowledge from physical sciences in real world contexts  *context standard 2 #5