Chem 322L Lab 1 report.docx - Experiment No 1 – Tools of...

Experiment No 1 – Tools of the Trade: Dilution, Calibration, and Error Analysis
Name:
University of South Carolina
Chem 322L
TA:
February 7, 2022

Abstract
The purpose of this laboratory experiment was to solve for an unknown concentration of
sucrose solution by substituting the density of the unknown sucrose solution into the equations
calculated for both the parallel and serial solutions.
After finding the unknown concentration, the slopes and y-intercepts of both dilution
techniques were compared to the class average, and a t-test was used to evaluate if the dilution
techniques differed from the class average for each dilution at the 95% level of confidence.
Introduction
This experiment required a knowledge of modern tools, used predominantly for
calculating mass and volume of solutions, preparing calibration curves based on data calculated,
and using data collected to calculate density of an unknown solution to compare previously
collected data, in this case, the rest of the class averages.
The relationship between density and temperature was observed and noted that density
was indirectly proportional to the temperature. A total of five sample were obtained for the
parallel dilution as well as five samples for the serial dilution. In a parallel dilution, a
concentrated stock solution is started with and new solutions are made with several different
milliliters of stock solution to different flasks, all ending with the same volume. In a serial
dilution, a concentrated stock solution is diluted in solution, but the diluted solutions that come
after that are taken from the previous diluted solution, decreasing in solution concentration for
each new sample.
Procedure
Four data tables were made to measure & record the calibrations of a 10-100 μL pipette, a
100- 1000 μL pipette, and the percent concentration of an unknown sucrose solution in a parallel
dilution and a serial dilution. The two pipettes were calibrated by first taring the balance to zero.
A weigh boat was placed on the scale, then tared to account for the mass of the water. Utilizing
both Eppendorf pipettes capable of measuring 10-100 μL and 100-1000 μL respectively, the mass
of any further added water and the set volume were recorded and steps repeated a total of three
times per volume measured. After the data calculation for the 10-100 μL pipette at volumes: 10,
25, 50, 75, and 100 μL, and the 100-1000 μL pipette at volumes: 100, 250, 500, 750, and 1000