Question

I need yo know this answer by midnight tonight. thanks.

you will need to construct your own data sheet for this experiment.

DATA ANALYSIS steps 1-2:
The colorimeter wsa used to measure teh absorbance of each of a series of [FeSal]+ solutions. A standard curve was constructed by plotting the absorbance vs. the concentration (M). The slope and y-intercept were found to be 1510 M^-1 and 0.001, respectively.
PROCEDURE:
An aspirin sample was prepared, following the procedure given in the experiment: hydrolyzing the 0.139 g of it with 5 mL of a 1 M NaOH (reaction 1), diluting this mixture to 50.0 mL (forming solution A), and taking a 1.00 mL aliquot of this solution an diluting it to 50.00 mL with 0.02 M Fe(III) (forming solution B - reaction 2). The absorbance of solution B was measured to be 0.366.
DATA ANALYSIS step 3:
(a) Use the measured absorbance and the standard curve's slope and y-intercept to calculate the concentration of [FeSal]+ in solution B.

(b) How many moles of [FeSal]+ were in the 50.00 mL of solution B?

(c) How many moles of sodium salicylate were in the 1.00 mL aliquot of solution A used to prepare soution B?
Hint: look at the stoichimetry of reaction (2) in the experiment to see how the moles of sodium salicylate realte to the moles of [FeSal]+.

(d) Given the number of moles of sodium salicylate in 1.00 mL of solution A (calculated above), how many moles are in the 50.00 mL of solution A?
Hint: This is not a dilution or Beer's Law problem. It is a simple multipication.

(e) Based upon the number of moles of sodium salicylate calculated in part (d), how many moles of acetlsalicylic, C9H8O4, were in the aspirin sample?
Hint: look at the stoichiometr of reaction (1) in the expt.

(f) Use the mass of the aspirin sample (given in the PROCEDURE section above) and the answer to part (e), coverted to grams to calculate the mass percent of acetlsalicyclic acid, C9H8O4, in the aspin sample.

Answer 1

a) given the equation in data analysis 1-2

and the Absorbance=0.366

The concentration of FeSal

b) Given the concentration

in the 50mL (0.05 L) the moles are:

c) Given the reaction:

The moles of Salicylate react 1:1 with Fe, to form 1 mol of FeSal thus

moles of Salicylate:

d) If in 1mL you have 1.21x10^-5 mol of salicylate

in 50 mL you have:

e)

Given the reaction:

The molar ratio is 1:1, thus the moles of acetilsalicylic acid are the same as the salicylate:

f)