100%(5)5 out of 5 people found this document helpful
This preview shows page 1 - 2 out of 5 pages.
Briana TurnerLab Report #2TA: Ryan WoodIntroduction:The purpose of this lab was to estimate Avogadro’s number using stearic acid. Wedropped a precise amount of stearic acid onto the surface of water using a well-calibratedpipette, enough to form a monolayer “cake” of molecules onto the surface of the water.The polar head of the stearic acid molecule and the non-polar end, which sticks awayfrom the water, allows a monolayer to form on the surface of water.From the volumerequired to form a monolayer, the number of drops of stearic acid was counted.Thethickness of the layer was then used to compute the volume of a singular carbon atom,and this value was then used to determine the volume of a mole of carbon atoms used.From this value, we were finally able to estimate Avogadro’s number.Experimental Methods:A 15cm watch glass was cleaned with detergent solution and rinsed with both coldand distilled water. The watch glass was then dried and placed on plain piece of whitepaper. 10mL of hexane was poured into a 50mL beaker. A plastic pipette was used toplace drops of stearic acid into a graduated cylinder. The number of drops required todeliver a volume of 1.00 mL was averaged from four trials. A 10mL graduated cylinder