Answer:
Hi. The answer are as follow:
The slope is equal to 0.0228
The coordinates of the intersection in "y" are (0,0)
The coordinates of the intersection in "x" are (0,0)
a) x = 20 ng/mL
b) x = 13.5 ng/mL
x = 13.9 ng/mL
x = 15.21 ng/mL
x = 18.07 ng/mL
In the attached Excel file you can see the graph
Explanation: Graphing the data using Excel gives the attached figure. Adding the linear trend line we obtain the equation and the coefficient R. As you can see in the figure, the equation is:
y = 0.0228x
R = 0.9413
Where "y" is the absorbance and "x" the concentration. The slope is equal to 0.0228.
To calculate the intersection in “y” we must take an x = 0. Replacing in the equation would give:
y = 0.0228*(0) = 0
so when x = 0, y = 0. The coordinates of the intersection in “y” are (0,0)
To calculate the intersection in "x" we must take a y = 0. Clearing and replacing in the equation would give:
x = y/0.0228 = 0/0.0228 = 0
So when y = 0, x = 0. The coordinates of the intersection in "x" are (0,0).
a) To calculate the concentration of the sample we will use the equation of the graph. We must clear "x" which is the concentration.
x = y/0.0228 = 0.456/0.0228 = 20 ng/mL
b) We use the same procedure as part a)
x = 0.308/0.0228 = 13.5 ng/mL
x = 0.317/0.0228 = 13.9 ng/mL
x = 0.347/0.0228 = 15.21 ng/mL
x = 0.412/0.0228 = 18.07 ng/mL
Greetings
