Absorbance A570 of an unknown BPB solution was found to be 0.445. Calculate the concentration in...
Question:
Absorbance A570 of an unknown BPB solution was found to be 0.445. Calculate the concentration in mg/mL of the unknown BPB (MW = 670) solution using the standard calibration curve below.
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Standard curve
In laboratory, standard curves are prepared in almost all experiments to calculate the concentration of compound/substance of unknown samples. Standard curve is also called the calibration curve. Basically pure compound solutions are prepared with known concentrations. The O.D. value of each solution is noted and a graph of O.D. vs concentration is prepared. If the points form a straight line, one can use a straight-line equation to find out the concentration of unknown samples by simply measuring their O.D.
Straight line equation is,
Y = mX + C
where Y= value at Y-axis, m=slope of straight line, C=intercept at Y-axis. X = value at X-axis.
If a straight line passes from 0,0 point, C becomes zero. Thus, X=(Y/m).
Answer and Explanation: 1
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View this answerConcentration of BPB sample can be calculated as follows:
The standard graph can be used first to find the slope of a straight line (refer to the...
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