Lab Report Spectrophotometric Analysis of Cu2+ PDF

Preview

Summary

Download Lab Report Spectrophotometric Analysis of Cu2+ PDF

Description

Copper Lab By: Jonathan Pilafas (performed on 11/5/2018)

Purpose: The objective of this lab is to determine the concentration of copper (II) ions in a solution of unknown concentration as a hypothetical example to determine if the concentration of the copper (II) ions meets or exceeds the action level established by the EPA.

References: 1. “Laboratory Experiments for Chemistry 121” - Harper College 2. http://dept.harpercollege.edu/chemistry/msds1/Copper%20metal%20Flinn.pdf 3. http://dept.harpercollege.edu/chemistry/msds1/Copper(II)%20Sulfate%20anhydrous%20 JTBaker.pdf 4. http://dept.harpercollege.edu/chemistry/msds1/Ammonia%202M%20Ethanol.pdf

Reagents: Name

Formula

Molecular Weight

Ammonia

NH3

17.031 g/mol

Copper Sulfate

CuSO4

96.06 g/mol

Copper

Cu

63.546 g/mol

Safety:

Ammonia: Health - 0 Flammability - 0 Reactivity - 1

Copper Sulfate: Health - 2 Flammability - 0 Reactivity - 1

Copper: Health - 4 Flammability - 3 Reactivity - 0

Methods: During part one of this experiment, my group filled cuvettes with various concentrations of Cu and water. Then we transferred these solutions to a spectrophotometer to measure the visible spectrum of each solution. During part two, we did the same testing for two concentrations of Cu that had been previously prepared before class. During part three, we analyzed our data and recorded them onto graphs to visualize the trend of our data.

Part A: Sample #/name

Volume of CuSO4 (mL)

Volume of H2O (mL)

[Cu2+]

1

***

0

2

5

Filled to 10 mL

3

3

Filled to 10 mL

4

2

Filled to 10 mL

5

1

Filled to 10 mL

A

***

0

B

***

0

C

***

0

Sample #/name

Sample # used

Volume of Sample # (mL)

Volume of 0.500M NH3 (mL)

1

1

1

2

2

2

1

2

3

3

1

2

4

4

1

2

5

5

1

2

A

A

1

2

B

B

1

2

C

C

1

2

Blank

DI H2O

1

2

Part B:

Instrument: Agilent 8453

Data:

Sample

[Cu2+]

Absorbance (AU)

1

0.0100M

0.20025

2

0.0200M

0.34153

3

0.0300M

0.54634

4

0.0500M

0.80986

5

0.100M

1.66220

A

unknown

0.44428

B

unknown

0.26682

C

unknown

0.74660

Calculations: Give a sample calculation for how [Cu2+  ] was calculated in each sample. -

The spectrophotometric device was used to calculate the [Cu2+] in each sample.

Show calculations for how the Cu2+  concentration was calculated in each the unknowns. -

The spectrophotometric device was used to calculate the unknown concentrations of [Cu2+].

Results and Discussion -

The concentration of my unknowns that I determined based on my data were 0.24 mol/L (Unknown A), 0.15 mol/L (Unknown B), and 0.41 mol/L (Unknown C).

-

The method we used to determine to concentration of Cu2+ wa very effective, which is shown in the significant accuracy of the trendline of our data.

-

No one in our group analyzed the same unknowns, so we could not report the differences found between trials.

-

Under the conditions of our lab, this is evident that the spectrophotometric device being used does an excellent job at discerning the concentration of copper and ammonia from water. Due to the sophistication of this device, we are able to ignore the dilution factor and are able to record accurate data as a result.

Conclusion: In this lab, we determined the concentration of copper (II) ions in a solution of unknown concentration as a hypothetical example to determine if the concentration of the copper (II) ions meets or exceeds the action level established by the EPA. We found the concentrations of the copper (II) ions that made up our various solutions through the sophisticated device that was the spectrophotometric device. Using this, my group found extremely accurate data on the concentrations of these solutions, allowing us to to validate this entire process as a result....