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omeli [17]
3 years ago
15

The standard curve was made by spectrophotographic analysis of equilibrated iron(III) thiocyanate solutions of known concentrati

on. You are asked to analyze a Fe(SCN)2+ solution with an unknown concentration and an absorbance value of 0.410 . The slope-intercept form of the equation of the line is y=4541.6x+0.0461 . The unknown was analyzed on the same instrument as the standard curve solutions at the same temperature. What is the Fe3+ concentration of the unknown solution?
Chemistry
1 answer:
posledela3 years ago
6 0

Answer:

Molar concentration of the Fe³⁺ in the unknown solution is 8.01x10⁻⁵M.

Explanation:

When you make a calibration curve in a spectrophotographic analysis you are applying the Lambert-Beer law that states the concentration of a compound is directely proportional to its absorbance:

A = E*l*C

<em>Where A is absorbance, E is molar absorption coefficient, l is optical path length and C is molar concentration</em>

<em />

Using the equation of the line you obtain:

y = 4541.6X + 0.0461

<em>Where Y is absorbance and X is concentration -We will assume concentration is given in molarity-</em>

As absorbance of the unknown is 0.410:

0.410 = 4541.6X + 0.0461

X = 8.01x10⁻⁵M

<h3>Molar concentration of the Fe³⁺ in the unknown solution is 8.01x10⁻⁵M.</h3>

<em />

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Explanation:

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When used as a diacritic mark, the term dot is usually reserved for the interpunct, or to the glyphs 'combining dot above' and 'combining dot below' which may be combined with some letters of the extended Latin alphabets in use in Central European languages and Vietnamese.

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