Drink mix concentrations and absorbances for constructing a standard curve Concentration (mm) Concentration (M) Absorbance
Sample 1 200 0.200 0.52
Sample 2 77 0.077 0.18
Sample 3 32 0.032 0.08
Sample 4 300 0.300 0.77
Sample 5
a. Plot your data of absorbance versus concentration (in M) using Excel. Add a trendline and display the equation of the line to determine the slope and y intercept. Please review the video on using Excel if needed. Enter the slope of the trendline
Enter the y-intercept of the trendline
b. Using the molar absorptivity (slope) determined from your plot, calculate the expected concentration (in M) of a drink mix solution with an absorbance of 0.66.
c. Choose the statement that best answers the following question
Can you use your plot to predict the absorbance of a 214 mM solution of nickel(II) chloride and why?
A. Yes, because the same instrument is used for the measurement of the new compound.
B. Yes, because you can use the same cuvette for the measurement of the new compound
C. No, because the determined absorptivity applies only to the compound measured.

What is the molecular formula for a compound that is 46.16% carbon, 5.16% hydrogen, and 48.68% fluorine? the molar mass of the compound is 156.12 g/mol

Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely. analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?

What is the percent by mass of oxygen in fe2o3