Wednesday, December 9, 2015

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.



































Wednesday, December 2, 2015

Ester Synthesis Lab

Carolina Wasinger
Chemistry
Ms. Bowser.
12/2/2015
Partner: Sophie Horn




Purpose:

To create different smells within a lab experiment transforming different smells into Esters and sweet smelling compounds. 


Procedure :
  1. Fill 50 mL beaker with 30 mL of water 
  2. Drop into the beaker, a boiling stone 
  3. Put the beaker on a hot plate and bring water to a boil
  4. Label test tubes with the following numbers: 1, 2 and 3
  5. Using the wafting technique, smell the acids and record in a data table. Add 5 drops of the respective carboxylic acids to each of the test tubes 
  6. Again, using the wafting technique, smell the alcohols and record in the data table (Bowser lesson 7). Add ten drops of each alcohol to to each tube (look in the following table)


Test tube:             Carboxylic Acid                Alcohol
1                             acetic acid                       isopentanol
2                             acetic acid                       butanol
3                             butyric acid                     ethanol

  1. Add 1 drop of the sulfiric acid (H2SO4) to each test tube
  2. Place a boiling stone into each test tube
  3. Carefully smell each compound by using the wafting technique
  4. Slice a plastic pipette to a length that is shorter than that of the test tube. Put the pipette into the test tube so that the bulb somewhat seals off the test tube
  5. Put the test tubes into boiling water n heat for 5 minutes, or until the compund no longer smells putrid
  6. After, remove the test  tubes from the water and turn off the hot plate
  7. Take the pipette out from the test tube. There should only be vapors in it
  8. squeeze the pipette and waft the vapors, Record the smell on the data sheet
  9. Dispose properly of chemicals (Bowser, Lesson 7)
Materials:

  • 50 mL beaker
  • Hot plate
  • 3 microscale test tubes
  • Boiling stones
  • 3 plastic pipettes
  • scissors 
  • pencil 
  • organic acids and alcohols
    • Acetic Acid C2H4O2
    • Butyric Acid  C4H8O2
    • Concentrated Sulfiic Acid  H2O4S
    • Ethanol C2H6O
    • Isopentanol  C5H12O
    • Butanol C4H10O
(Bowser, lesson 7)

Safety:

Hot Plate; Hot plate can burn. Do not  directly touch the heated surface of the hot plate and use tongs to move items on and off the hot plate (Common knowledge). 

Boiling Stones: Hazardous if swallowed or if comes in contact with eyes in powder form. (Material Data Safety Sheet). 

Acetic Acid, can be erosive to the skin. Keep out of eyes and off skin and clothing (CDC). 

Butyric Acid, Is corrosive to skin, combustible and flammable. Keep away from open flames (CDC). 

Sulfuric Acid. Is corrosive to skin and can cause burns to skin (CDC). 

Ethanol: Can be hazardous id swallowed or if comes into contact with eyes and skin (CDC). 


DATA:



Test Tube #
Smell of Carboxylic Acid
Smell of alcohol
Smell of mixture before heating
Smell of mixture after heating
1
Vinegar
Medicinal
Cherry flavored medicinal syrup
Sweet, fruity
2
Vinegar
Sharpie
Chemically
Slightly like gasoline
3
Putrid
Rubbing alcohol
Putrid
Cherry, sweet fruity medicinal.

After 1 minute: the liquid at the bottom of the test tubes turned yellow (because there is a chemical change that is happening). After, the contents turned to a light pink color.

Background: 
The word Synthesis in this experiment means bringing together specific compounds through a controlled experiment (Bowser lesson 7). 

The sweet-smelling molecules known as Esters have a key structure piece in all of them: A Oxygen atom linking to Carbon atoms one of which is double bonded with another Oxygen atom (Stacy). 

Carboxylic Acids are putrid smelling molecules (Stacy). The key piece in a the structure of a carboxylic acid is an Oxygen atom singly bonded with a hydrogen, and on the other side, a carbon atom. The carbon atom is doubly bonded with a separate Oxygen atom (Stacy). 

Alcohols often smell very strongly medicinal (Stacy). A key part of an alcohols structural formula is a hydrogen singly bonded with an Oxygen atom (Stacy). 

A catalysts role in an experiment is to help the reaction to take place or speed it along (Stacy). Catalysts are not consumed into the reaction (Stacy). 

Analysis:

       From the questions of lesson 8 we analysed the chemical reaction that occurred in the lab. None of the mixtures smelt sweet in the beginning of the lab but rather putrid or strongly medicinal, in the end, all of the compounds should have smelled sweet. 
      In the final molecule, the Ester functional group was present in all three of the compounds. To build new molecules, two hydrogen atoms and an oxygen were taken out of the compounds and the remainder of the two compounds were added together, forming the alcohol and acid mixture. 
     We know from the color changing of the liquids that a chemical reaction was taking place in the test tubes. 


Graphs:



Conclusion:
In conclusion, the chemistry students were able to create new smells and transform organic acids and alcohols from putrid or medicinal to sweet. 

Discussion of Error: Errors in this lab could of occurred to errors such as heating liquids too long but also the perceptions of the different smells. 

Questions:
5.)


  • C8H16O2
  • C7H14O
  • C9H18O
  • C6H12O2

6.)

  • Isopentyl Methanate
  • Butyl Caproate
  • Ethyl Salicate. 
Citations:

Acetic Acid. (N.d.). In: Center for Disease Control and Prevention: NIOSH Pocket Guide to Chemical Hazards. Retrieved from: www.cdc.gov.

Bowser. (2015). Create a Smell Ester Synthesis. [Lab worksheet]. Chemistry. Foxcroft School. Middleburg, VA.

Bowser. (2015). Making scents analyzing Ester synthesis.  [Lab worksheet]. Chemistry. Foxcroft School. Middleburg, VA.

Butryc Acid. (N.d.). In: Center for Disease Control and Prevention: NIOSH Pocket Guide to Chemical Hazards. Retrieved from: www.cdc.gov.

Carborundum Boiling Chips. (N.d.). In: GFS Chemicals: Material data safety sheet. Retrieved from: sds.gfschemicals.com/atn/CARBORUNDUM%20BOILING%20CHIPS%2c%2014%20MESH_Default_MSDS%20US.pdf

Ethyl Alcohol. (N.d.). In: Center for Disease Control and Prevention: NIOSH Pocket Guide to Chemical Hazards. Retrieved from: www.cdc.gov.

Stacy. Angelica. M. (2011). Chapter 2, section 6. Ladie Malek, Jeffrey Dowling. Living by Chemistry (168-171). Emeryville, CA. Key Curriculum Press.

Sulfuric Acid. (N.d.). In: Center for Disease Control and Prevention: NIOSH Pocket Guide to Chemical Hazards. Retrieved from: www.cdc.gov.

Caroline Magnani helped me with graphs section.