Spectroscopy Method Utilized in the Lab - Essay Example

The spectrometer cannot determine the quantity of light absorbed(A) by a certain solution unless calibration is done first. The opposite of Transmittance (T %) is Absorbance (A) which can be defined as the quantity of light that is absorbed or transmitted through a sample. Moreover, a highly concentrated solution is, the more it absorbs light, and the less transmitted light through the solution is. This also implies that the concentration of a particular solution is directly proportional to the rate of absorbance, a fact that Beer-Lambert’s Law has proved.

The Law states that the quantity of light that is absorbed by a given sample is dependent on the concentration of that sample (C), the species absorbing, the wavelength of the light used together with the thickness of the sample: A = £bC (where A is absorbance, £ is a constant when the identity of the absorbing species and the wavelength of the light utilized are not altered, b is the solution’s thickness in the cuvette container, and C is the sample’s concentration)(Bauer et al.110). By utilizing a standard curve(y=mx+b), where x-values show various concentrations of the same sample with y values showing the absorbance of a given wavelength, it can be stated that the concentration is directly proportional to the absorbance, which initially was proved by Beer-Lambert Law(Bauer et al.110).

The percentage of Mass can be defined as the mass of a definite element over the total mass of all elements multiplied by 100%(Brown et al.85). Through the establishment of a standard for the copper nitrate compound and utilizing the knowledge of Beer-Lambert Law, the % mass of the copper in the ore was attained.
2. Procedure:
Materials:
• 8.5 mL HNO3
• 4.5 g Cu(NO3)2 * 2.5 H2O
• Graduated cylinder
• Pipette
• Calorimeter with Lab Quest software
• Erlenmeyer flask
• Filter with a vacuum
• 4.5 g of ore

Determination of the 8.5 mL of nitric acid would dissolve the copper compound Cu (NO3)2* 2.5 H2O was done in the first week of the lab experiment. In addition, 8 serial dilutions were carried out by adding an increasing quantity (beginning with 8.5mL) of nitric acid (HNO3) to 4.5 g of Cu (NO3)2 * 2.5H2O. The quantity of red light ((λ=635nm) absorbed by every diluted solution was established using a calorimeter with Lab Quest software. Sketching of a standard line graph was done by plotting the absorbance against the concentration(C%).

The second week of this lab saw 4.5g of the ore dissolved in 8.5mL of Nitric acid (HNO3) and the surplus quantity of sand filtered out of the liquid solution by use of a filter hooked up to a vacuum. The quantity of red light ((λ=635nm) absorbed by this solution was determined by the use of a calorimeter with Lab Quest software. Making use of the formerly sketched straight-line function(y=mx+b), determination of the concentration (C %) of the ore was done. Repetition of this experiment was done twice for a sum of 3 trials. Finally, the percentage mass of Cu2+ available in the ore was determined and suggestions were sent to geologists concerning the drill sites.