Experiment 4 Spectroscopic Determination of Nickel in aqueous

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Experiment 4 Spectroscopic Determination of Nickel in aqueous solution.

Please hand-in Prelab for experiment 4. Report: Full report Format:

Purpose

:

One or two sentences to state the objective of this experiment

Procedure

:

Do not rewrite the recipe. Instead write the following line.

As in Chem 120 lab manual, Camosun College, Fall 2009, Edited by Dr. Neil Meanwell, pages 17-20.

Note: If there are any chances to the lab, please include it here. Also include solution concentrations here

Data and Results Tabular format - give tables with a descriptive title heading. ie. Table

1 Determination of

max for a Nickel solution.

Calculations

show sample calculations, here. If they are repetitive, then do it once only. Concentration from graph (mol) x 50.0 mL x 1L x 58.7g x 1000 mg L 1000 ml 1 mol 1 g

Graph

Refer to this as Figure 1. Give a descriptive title. Do not just say Absorption versus concentration

. Please plot graphs on graph paper. (1 mm x 1 mm)

Discussion

:

Provide a brief discussion of the theory (what is spectroscopy?) How is it used to provide quantitative information. (You can use Wilkipedia, but don’t forget to say this in your own words). Why do you need to record the wavelength at maximum absorption? What is a calibration curve? Also provide a bibliography to your source. You may use a superscript number 2 . Then this is referenced in the bibliography section (see below)..

Refer to your tables and figures.

Table 1 shows the maximum wavelength for absorption. What does this mean? What is it telling you? Table 2. what is this for? What does it give? Is the trend consistent to Beer’s Law? Does it give a straight line? Should it pass through the origin? What may be the reason why it doesn’t pass through zero? What are the sources of errors? Write in third person passive tense, no point

form

– Your discussion should be written with complete sentences.

Conclusion:

One sentence

to answer the purpose of the experiment What is the concentration of the Nickel unknown solution in mg/L with ID number?

Reference:

1. Johnson, D.A, “Some Thermodynamic Aspects of Inorganic chemistry, 2 nd ed, Cambridge University Press, Cambridge,

1982

, pp. 158-168 2. Moore, Michael. (n. d.). Moore collection: Underground comix. < http://www.lib.calpoly.edu/spec_coll/comix/index.html

>. Accessed September 30, 2001.

Experimental:

Preparation of standards

Nickel stock solution has a 0 10 20 Title - descriptive X

Preparation of unknown

30 40 50 Abs X X X best f it straight line slope = y2-y1 x2-x1 use graph paper (1mm x 1mm) or excel concentration (mol/L) Make stock solutions - Make unknown Use stock solution (one of them (25.0 mL) to find  max (scan 370 – 500 nm. Use stock solution to prepare calibration curve.

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