Unknown Concentration

Words: 1022

Pages: 5

Open Document

The objective of this lab was to find the concentration of iron in a solution with an unknown concentration. Through the use of the Beer-Lambert Law and spectrophotometry, one can find the absorbance of solutions with known concentrations of iron and create a calibration curve that can be used find the concentration of the unknown solution, which was calculated to being 10.5ppm Fe. This value is somewhat precise due to its relative standard deviation of 1.65%, and the errors were kept to a minimum to increase accuracy.

I. Introduction
The purpose of this lab was to identify the unknown concentration of iron in a solution by qualitatively measuring the absorbance of electromagnetic radiation by the molecules in a solution. To examine …show more content…
Then the lab quest and spectrophotometer were prepared by setting the wave length to 508nm, the units to % transmittance, and the mode to “Events with Entry” and then the spectrophotometer was calibrated with a cuvette of solution A. Now that the lab quest was ready, the % transmittance was calculated for solutions B-I and recorded. Then the lab supplies were cleaned and put away.

III. Results and Discussion
Data:
Unknown Solution: Fe0257
Mass of ferrous ammonium sulfate: 0.0154
Concentration of the stock iron solution: 10.5 ppm Fe

Calibration Curve:

Solution
Volume of Stock Iron Soln. used (mL)
Conc. Fe in Calibration Solns. A-F (ppm)
Measured %T
Calculated Absorbance
A
0.00
0.000
99.993
0.00003040
B
2.00
0.110
98.861
0.004975
C
5.00
0.274
88.145
0.05480
D
10.00
0.548
80.123
0.09624
E
25.00
1.37
55.128
0.2586
F
50.00

Essay on Lab Report: Protein Concentration

protein concentration and its absorbance at 610nm. The independent variables are in the X-axis, and the dependent variables are in the Y-axis. The trend has a R2 value of 0.9812 Table 1: The representative data of the actual protein concentration in A-Rice, B-Cow’s milk, and C-Protein shake respectively and their theoretical protein concentration contents labeled on each of the product with the related percentage error. Unknown sample Absorbance at 610 (nm) Calculated protein concentration (g/mL)…

Words 432 - Pages 2

Electromagnetic Radiation and Concentration Curve Essay examples

purpose of this lab is to evaluate light absorption in a variety of solutions to identify an unknown solution’s concentration by using a spectrophotometer to measure a particular substances absorption of radiation at a precise wavelength in the visible region of the spectrum to construct a concentration curve. This was then compared to the peak of absorbance of the unknown to determine the concentration of the unknown substance (Kotz, 2014). Spectroscopy is the study of light, which can be thought of as…

Words 379 - Pages 2

Essay on Instro Lab 6

Stock, Substock, and External Standard Solutions 1 Regression Method 4 Single Point Approach 7 Summary of Results and Unknown Identification 11 Qualitative UV Spectrum 13 Discussion 14 References – 16 Table of figures Figure 1 Representing the preparation of external calibration standard solutions from caffeine stock solution 3 Figure 2- Representing the dilution scheme of unknown power drink sample 4 Figure 3 Chemical structure of Caffeine(2) 13 DETERMINATION OF CAFFEINE IN SPORTS DRINKS USING…

Words 2110 - Pages 9

Total Protein Essay

levels of protein can indicate infections such as hepatitis or HIV, while lower levels can entail haemorrhaging or malnutrition. Through application of solutions in a spectrophometer individuals can define the concentration of a material due to Beer’s law. The law states that the concentration of a substance is directly proportional to the amount of light it absorbs. The total number of proteins in a substance can help decide what the state is of an individual’s blood cells and tissues are.…

Words 1083 - Pages 5

Unknown Sample Lab Report

An experiment was deliberated to determine if the concentration of select unknown samples exceeded a certain amount that corresponded to the U.S. standard. The concentrations were obtained using a series of calculations and equations via a spectrophotometer, which was the main piece of equipment that provided the percent transmittance. The unknown samples were tested against the diluted stock-AVM solution. It was founded that all selected unknown samples, in fact, did not exceed the U.S. standard…

Words 946 - Pages 4

Essay about BCHM 4124 Spring 2014 Final 9 Naomi Rodman Robert Burnham

9: Sugar Analysis Performed: April 9, 2014 Due: April 18, 2014 Writer: Naomi Rodman Reviewer: Robert Burnham Unknown 11 “I have neither given nor received unauthorized assistance on this assignment” Objective: Determining the glucose and mannose concentration of an unknown solution by finding the total carbohydrate concentration via a BCA assay and the glucose concentration using a hexokinase (HK) coupled reaction. Results (BCA Sugar Assay; Glucose + Mannose Analysis): The components…

Words 1677 - Pages 7

Unknown Lab Report

Identification of Three Unknowns Leah Bacon December 10, 2014 Chemistry 3020 M/W 1:25 - 4:25 William DeBenedetti Abstract Molecular structure can be determined by Fourier Transform infrared spectroscopy [IR, herein] by accurately identifying residues. IR is extremely sensitive to molecular structure because it measures the change in a molecule’s dipole moment due to vibrations caused by light absorbance. In this study, a variety of IR techniques were used to identify the composition of two unknowns by comparing…

Words 3228 - Pages 13

Spectrophotometric Analysis of a Two-Component Mixture Essay

determine the concentrations of permanganate in a mixture of unknown. Abstract: Working standards of dichromate and permanganate were prepared and absorbance for each found. This was done in order to plot a graph of absorbance versus concentration, from which the concentration of permanganate and dichromate in the unknown sample could be determined. Sulphuric acid was added to the standards in order to force the reaction to completion. Wavelengths…

Words 1878 - Pages 8

Determination of Redusing Sugar Using Dns Method Essay

environmental temperature. Acid hydrolysis was carried out through reflux boiling for 20 minutes with 10ml 0f 1.5M concentrations of diluted sulphuric acid. Reducing sugars concentrations were determined by spectrophotometry using the 3, 5 dinitrosalicylic acid (DNS) method. The first sample was operated as blank for zero. The stock solution was prepared in order to find the unknown concentration of carbohydrate cereals…

Words 2902 - Pages 12

Acetylcholine And Physostigmine Research Paper

Acetylcholine and physostigmine Physostigmine inhibits the metabolism of acetylcholine and indirectly stimulates nicotinic and muscarinic receptors As acetylcholine is not broken down/metabolised, physostigmine increases the concentration of acetylcholine at the sites of the cholinergic transmission. 2. List the interactions where a decrease in the agonist’s effect is seen, and for each one briefly explain why there is a decrease. Acetylcholine and Promethazine Promethazine acts as an anticholinergic…

Words 404 - Pages 2