CHEM 06101 Study Guide - Spring 2018, Comprehensive Midterm Notes - Concentration, Ion, Acid
12 Oct 2018
School
Department
Course
Professor
CHEM 06101
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Abstract of Accurately Preparing Solutions of Known Concentration
The purpose of this lab experiment was to prepare different concentration solutions, getting
knowledge of using correct equipment to prepare accurate solutions, and learning how to use
spectrophotometer to measure the amount of light absorbed by solutions. In this experiment I and
my lab partner had prepared different concentration solution from three different known
solutions KMnO4, K2CrO4, and Cu(CH3COO)2•H2O. Firstly, we prepared 100 ml of 0.125M
solution using 2.501g of copper (II) acetate and then we prepared diluted Cu(CH3COO)2•H2O 25
ml of 0.001M and then using cuvettes and spectrophotometer we found the absorbance of 0.430
A at a wavelength of 610nm and the percent error is 14.4%. Moreover, we prepared 100ml of
0.002M solution using 10ml of KMnO4, and then we prepared 25 ml of 0.001M KMnO4, using
5ml of 0.002M KMnO4 and the absorbance of this solution was 0.776 A at a wavelength of
530nm and the percent error is 7.19%. Lastly, we prepared 10 ml of 1.25x10-3M K2CrO4
Solution using 7ml of stock solution of K2CrO4. Absorbance of K2CrO4 is 0.318 A at a
wavelength of 440nm and the percent error is 21.6%. I can Inference that pipet was most
accurate instrument to measure out the solution from volumetric flask
.
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Summary of Accurately Preparing Solutions of Known Concentration
In this lab the absorbance of light of KMnO4, K2CrO4, and Cu(CH3COO)2•H2O is less than 1,
and the percent error of all three solutions are closely related. According to my results and
calculations I have met all the objectives such as, calculated the amount of solution to use to
prepare different molarity solution, and other objective was to master in using equipment that
give accurate results. There was complication in finding percent error of KMnO4 because the
value of “a constant” was really high 1.8x104 that the percent error value getting higher, and then
I used 1.8x103 as a constant value which gave me correct answer of 7.19% earlier I was getting
828% which was very high value for percent error. This experiment helped me to review some
chemistry 1 topics and recent chemistry 2 topics such as finding molarity, percent error, and
calculating absorbance. I can use the skills that I have learned from this experiment in real life
and in chemistry classes.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Abstract of accurately preparing solutions of known concentration. The purpose of this lab experiment was to prepare different concentration solutions, getting knowledge of using correct equipment to prepare accurate solutions, and learning how to use spectrophotometer to measure the amount of light absorbed by solutions. In this experiment i and my lab partner had prepared different concentration solution from three different known solutions kmno4, k2cro4, and cu(ch3coo)2 h2o. Firstly, we prepared 100 ml of 0. 125m solution using 2. 501g of copper (ii) acetate and then we prepared diluted cu(ch3coo)2 h2o 25 ml of 0. 001m and then using cuvettes and spectrophotometer we found the absorbance of 0. 430. A at a wavelength of 610nm and the percent error is 14. 4%. 0. 002m solution using 10ml of kmno4, and then we prepared 25 ml of 0. 001m kmno4, using. 5ml of 0. 002m kmno4 and the absorbance of this solution was 0. 776 a at a wavelength of. Lastly, we prepared 10 ml of 1. 25x10-3m k2cro4.
