Colorimetric Determination of Iron in Vitamin Tablets, Lab Report Example

Colorimetric processing is the assessment of the quantity of color that is present in a material. The complexes which are formed from transition metals create vividly colored aqueous solutions which take place as an outcome of the electrons migrating in the energy shells between the metallic core and the shells within the ligands. The transitions of electrons possess energies correlated to wavelengths found in the regions visible to the linear segments documented in the atomic spectrum of hydrogen. As the chemical sample assimilates radiation, the absorbance assessment is applied. The absorbance assessments are applied by evaluating the quantity of light which ingresses into as chemical sample I₀ to the quantity of light the ewgr4esses from the sample I. This relationship is designated as transmittance T= I- I_0. As the chemical sample assimilated radiation, the value of I₀ is superior to I. This causes the value of T to become fractional. The formula that is applied for calculating absorbance is A = -log T (APSU 1).

The green light was applied due to the propensity of the impurities that may have been present in the iron solution to create their proprietary complexes. The absorbance measurements would be influenced. Consequently, the tabulation of the concentration of iron (II) would be influenced. The green light enables the process of colorimetric to be highly selective. Consequently, the reagent solution does not manifest any absorbance with green light (Ahmed 710).

The formula that is applied is c= ?v. The wavelength is 520 nm = 5.2 x 10^-7 m.  The constant c is equivalent to 3.0 x 10⁸ m/s. The frequency v can be calculated by 3.0 x 10⁸ m/s / = 5.2 x 10^-7 m = 5.769 X 10¹⁴ s^{– 1}. The energy in Joules for one photon of light would be determined as E = hv, where h is Planck’s constant. (5.769 x 10¹⁴ s^-1) (6.626 X 10^{– 34}Js) = 3.8225394 x 10^-19J = E. Consequently, the energy required for one photon would have a frequency of = 5.769 x 10¹⁴ s^{– 1}. = 5.769 x 10¹⁴ s^{– 1} and energy of 3.8225394 x 10^-19J.

Twice the absorbance is 0.942. 0.942 = 0.3X – 0.0637. The equation is transformed to 0.3X = 0.8783. Multiplying 0.8783 x .3.333= 2.9273. The concentration of the iron in STD2 is 2.9273 x 0.0056 mol/ L. The concentration would be 0.0163933 mol/ L.

5.0 = 0.3X – 0.0637, 4.9363 cm = 0.3X, X= 16.45269. The new concentration for the STD 2 would be 0.092135 mol/L.

Works Cited

APSU. “Colorimetric determination of Iron in vitamin tablets.” Austin Peay State University, 2015. Web 29 April 2015. https://www.spsu.edu/sites/apsu.edu/files/chemistry/Colorimetric_Determination

Ahmed, M. Jamaluddin and Uttam Kumer Roy. “A simple spectrophotometric method for the determination of iron (II) aqueous solutions.” Turk J Chem 33(2009): 709- 726.

Kent’s Chemistry. “Wavelength (?), Frequency (v) and Energy Calculations (E).” Kent’s Chemistry Homepage, 2015. Web 29 April 2015.   http://www.kentchemistry.com/links/atomic structure/wave eqautions.htm