Carolina Wasinger
Chemistry I
12-9-2015
Ms. Bowser
With Partner: Sophie Horn


Purpose:
To discover which liquids are attracted to a negatively charged wand; from this, determine which molecules are polar and nonpolar. Also to observe the property of cohesion in each of the liquids through an experiment involving placing droplets of the substances on waxed paper.

Materials:

• Glass wand
• Cheese cloth
• Beaker
• Syringe (to create the stream)
• Water
• Isopropanol
• Hexane
• Acetic Acid
• Waxed paper. 
• Pipette. 

Procedure:

• For each liquid, pour the respective liquid in a steady stream and hold a charged wand (charge by rubbing a glass wand with a cloth.) next to the running stream, 
• Observe whether or not the stream bends/ is attracted towards the wand. 
• Next, use a pipette to drop droplets of the liquids onto a piece of waxed paper and observe the shape the liquid takes (or does not).

Background:

A polar molecule is a molecule whose atoms contain different electronegativity values and therefore attract additional electrons (Stacy). Nonpolar molecules contain atoms of equal or very similar electronegativity values (Stacy). Polar molecules tend to mix easily with water and have cohesive properties (Bowser). Cohesive properties means the molecules stick together in order to create surface tension; which is what creates perfectly round drops for molecules like water and acetic acid.

Data:

Compound	Effects of Charged Wand	Behavior on Waxed Paper
Water	Attracts	Round drop
Acetic Acid	Attracts	Round drop
Isopropanol	Attracts	Spreads thinly
Hexane	Does not Attract	Spreads thinly

Analysis:

Water Molecule:

Acetic Acid

Isopropanol Molecule.

Hexane Molecule:

Conclusion:

This lab demonstrated the properties of polar and nonpolar molecules as evidenced in the liquids reaction to the charged wand and wax paper.
Water, Acetic Acid and Isopropanol were all polar.
The only nonpolar molecule was Hexane.

Discussion of error:

In this lab error occurred for mainly the reason that there was not a sure way of determining if the wand was properly charged.



Citations:
Water molecule, http://blog.science-matters.org/2012/04/10/drawing-lewis-structures/

Acetic Acid molecule, http://chemistry.about.com/od/factsstructures/ig/Chemical-Structures---E/Ethanoic-Acid---Acetic-Acid.htm

Isopropanol Moecule, ww.123rf.com/photo_30181595_stock-vector-structural-chemical-formula-of-isopropanol-molecule-2d-and-3d-illustration-isolated-on-white-backgro.html.

Hexane Molecule, 

http://www.edinformatics.com/interactive_molecules/3D/cyclohexane_molecule.htm.

Attractive Molecules. Attractions between molecules. Lesson 15 lab packet. Handed out by: Lindsey Bowser. December 10 2015. Chemistry 1. Period A Foxcroft School, Middleburg VA.

Bowser. (2015). Attractive Molecules: Attractions between molecules.  [Lab worksheet]. Chemistry. Foxcroft School. Middleburg, VA.

Stacy. Angelica. M. (2011). Chapter 2, section 15. Ladie Malek, Jeffrey Dowling. Living by Chemistry (168-171). Emeryville, CA. Key Curriculum Press.