 Pectrophotometry is a technique that works on the principle of absorption of light by analyte present in the sample across UV visible electromagnetic spectrum. Today we are going to use that technique for analysis and quantification of potassium per magnet present in the sample. For that we have Pectrophotometer original solution that we called sample and standard dilution of potassium per magnet from 0.1 milligram per emul to 0.5 milligram per emul. We have droppers, we have two glass keywords, one for the reference test and the second one for the sample test. Coming towards the spectrophotometer, this part is called monitor of spectrophotometer that gives us visual about our experimental work. The lower one is called control panel that enable us for setting the parameters for our experimentation. This chamber of spectrophotometer have the cell holder that holds the glass qubit in it. For quantification of the potassium per magnet first we will run the reference test. For that we will add the solvent in the glass qubit, here we need to take the precaution. There are two different sides of glass qubit, it has two opposite sides, two opposite transparent sides of the glass qubit and two opposite opaque side of the glass qubit. While putting into the holder we must take precaution, the transparent side of glass qubit must face the light beam of spectrophotometer, we will add the solvent in the next glass qubit and put the glass qubit in the reference holder. Now we will select the parameters for absorbance, we will select the quantification, here we can see 400 nanometer wavelength is selected but potassium per magnet absorbs the light range between 525 nanometer to 530 nanometer. So we will change the wavelength by pressing F1 to change the parameter of wavelength, by pressing 2 we will select the wavelength and we will put our desired wavelength that is 525 nanometer and we will enter here wavelength is selected that is 525 nanometer. Now we will return for our experimentation, now we will start for reference, now we will take out the glass qubit and we will discard the solvent, now we will take the absorbance of our standard dilutions of potassium per magnet, first we will take the absorbance of solution of potassium per magnet that is 0.1 milligram per amper, we will press the start button for absorbance, we will take out the sample and discard, before taking the absorbance of second dilution of potassium per magnet we need to wash the glass qubit with distilled water, now we will take the absorbance of second dilution of potassium per magnet that is 0.2 milligram per amper, before putting into the holder we need to clean the transparent side of glass qubit with tissue paper so that maximum light from the light lamp can pass through it, we close the cover and press the start button to take the absorbance, now we will take out the glass qubit, wash again with distilled water clean it, now we will take the absorbance of third standard dilution of potassium per magnet that is 0.3 milligram per amper, again we will clean the transparent side of glass qubit before putting it into the cell holder, press the start button to take the absorbance, we will take out the glass qubit and discard the sample, again clean it with the distilled water shake slightly discard it into the bin, let's clean it, now further we will take the absorbance of fourth standard dilution of potassium per magnet that is 0.4 milligram per amper, we will clean the transparent side of glass qubit before putting it into the cell holder, we close the lid, press the start button to take the veneer, again we will take out the glass qubit, discard the sample, wash it with the distilled water shake it slightly and dry it, now we are going to take the absorbance of our last standard dilution of potassium per magnet that is 0.5 milligram per amper, we will clean the transparent side of the glass qubit, it is very necessary that allows the maximum light pass through it, we put into the cell holder, close the lid, press the start button to take the veneer, we will take out the glass qubit and discard the sample, we will clean it with distilled water shake it nicely and discard it, so far we have taken the absorbance of our standard dilution of potassium per mega net, now we will take the absorbance of our sample whose concentration is unknown to us, after the cleaning of glass qubit we will take the solution from our sample, clean the transparent side of the qubit and put it into the cell holder, close the lid and press the start button to take the veneer, we will take out the glass qubit, discard the sample, clean it with distilled water, now we have taken the absorbance of our standard solution of potassium per mega net and the sample of potassium per mega net solution whose concentration is unknown to us, now we will use that data of absorbance in the standard curve method to find out the concentration of potassium per mega net that is present in our sample, what is the first standard solution of potassium per mega net that is 0.1mg per mf, second standard solution of potassium per mega net that is 0.2mg per mf, third standard solution of potassium per mega net that is 0.3mg per mf, this is the fourth standard solution of potassium per manganade that is 0.4 milligram per ampere. This is the fifth standard solution of potassium per manganade that is 0.5 milligram per ampere. So far we have taken the absorbance of our standard solution of potassium per manganade and the solution of potassium per manganade in which the quantity is unknown. So we will use that data for the standard curve method to find out the concentration present in our sample. So we will perform the calculation on the smart board. The data we have taken from the absorbance of our standard solution of potassium per manganade and the sample solution of potassium per manganade will use it in the standard curve method to find out the concentration of potassium per manganade in our sample. For that purpose we will use the standard curve method to find out the concentration. So here I have taken the concentration at x axis and absorbance value at y axis. Here you can see the concentration of standard solution of potassium per manganade are 0.1 milligram per ampere to 0.5 milligram per ampere. So I will put the values on x axis 0.1, 0.2, 0.3, 0.4 and 0.5 milligram per ampere. So I am going to take the absorbance of standard solution of potassium per manganade at y axis. So I will set the scale 1, 2, 3, 4 and 5. If I look into the absorbance of 0.1 milligram per amel of potassium per manganade that is 1.2. So here approximately that is the point where I can meet the absorbance value of 1.2. For concentration of 0.2 milligram per amel the absorbance value is 1.9 somehow near close to the 2. The absorbance value of 0.3 milligram per amel is 2.3 slightly above the 2. Coming toward the absorbance value of 0.4 milligram per amel that is 3.1. So it is slightly above the 3 somehow here. Now I will put the value of standard solution that is 0.5 milligram per amel and its absorbance value is 4.2 somehow close to the above the 4. So that is the graph is generated that data will generate a a straight line a slope line denoted with m and that slope line will intercept at y axis it is also known as y intercept and denoted with b. So when I am going to put the absorbance value of unknown solution that is 2.5 that is somehow near between the 2 and 3. So when I will draw the line absorbance of unknown solution I will draw the line it will intercept somewhere at slope m that point is known as x and when I will draw it down it will give me a concentration that is approximately 0.29 milligram per amel. So that is how we can find out the concentration of potassium per manganade through standard curve method.