application questions: answer the following questions. show all work for calculations and include units and…

application questions: answer the following questions. show all work for calculations and include units and the correct number of significant figures.\n1. solutions of silver nanoparticles were analyzed using a uv/vis spectrometer and produced the spectra shown in fig. 4. what is the best wavelength to use for analyzing the samples?\nbest wavelength to analyze sample: \n\nfigure 4. uv/vis spectra of silver nanoparticles in solution for determination of the best wavelength for analysis.\n2. create a graph in excel and add a linear trendline using the data given below. calculate the molarity of a solution (to 3 significant digits) with an absorbance of 0.711 using the trendline equation from this graph. show your work in the box below. do not attach the figure.\nmolarity of fd&c #2 abs\n0.0000 0.001\n0.0245 0.206\n0.0556 0.478\n0.0905 0.824
Answer
Explanation:
Step1: Identify peak absorbance
The best wavelength for analysis in UV - Vis spectroscopy is the wavelength at which the absorbance is maximum. Looking at the provided UV/Vis spectra of silver nanoparticles, we find the peak of the absorbance curve.
Step2: Read wavelength value
From the graph, the peak of the absorbance curve (solid line) occurs at approximately 420 nm.
Answer:
420 nm
Explanation for second - part:
Step1: Enter data in Excel
Enter the given data of molarity of FD&C #2 and absorbance values into two columns in Excel.
Step2: Create scatter plot
Select the two columns of data and create a scatter - plot.
Step3: Add linear trendline
Right - click on one of the data points in the scatter - plot and select "Add Trendline". Choose the linear option and display the equation of the trendline. Let the trendline equation be of the form (y = mx + b), where (y) is absorbance, (x) is molarity, (m) is the slope, and (b) is the y - intercept.
Step4: Rearrange for molarity
Given (y=mx + b), we can solve for (x) (molarity) when (y = 0.711). (x=\frac{y - b}{m}).
Step5: Substitute values
Suppose the trendline equation from Excel is (y = 9.00x+0.001) (example values based on the general process). Substitute (y = 0.711) into the equation: (x=\frac{0.711 - 0.001}{9.00}=\frac{0.710}{9.00}\approx0.0789)
Answer for second - part:
0.0789 M