Not asking for answers necesarily but I would to know how to approach each question

Mass of pure acetylsalicylic acid (ASA) : .508 g

Dilution Absorbance (a.u.)
2:11 .116
4:11 .259
6:11 .392
8:11 .502
10:11 .548

Mass of tablet : .380 g
Absorbance read on the Spec 20 : .314 a.u.
Concentration of the solution : 5.42e-4 M

Using reverse dilution, calculate the concentration of the tablet in the 100 mL diluted solution.

M

Calculate the number of moles in the 100 mL diluted solution.

moles

Calculate the mass (g) in the 100mL diluted solution.

g

Determine the mass of ASA in 250 mL.

g

Determine the % of ASA in the tablet.

Determine the number of grains of ASA.

To approach each question, here are the steps you can follow:

Using reverse dilution, calculate the concentration of the tablet in the 100 mL diluted solution:
- Use the dilution equation C1V1 = C2V2, where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.
- Plug in the given values: C1 = 5.42e-4 M (from the question), V1 = 100 mL, V2 = 250 mL (since you want to find the concentration in 100 mL when the final volume is 250 mL).
- Solve for C2, which will give you the concentration of the tablet in the 100 mL diluted solution.
- The result will be in Molarity (M).

Calculate the number of moles in the 100 mL diluted solution:
- Use the formula moles = concentration * volume.
- Plug in the values: concentration = the concentration of the tablet in the 100 mL diluted solution (from the previous question), volume = 100 mL.
- Solve for moles.
- The result will be in moles.

Calculate the mass (g) in the 100 mL diluted solution:
- Use the formula mass = moles * molar mass.
- The molar mass of ASA (acetylsalicylic acid) can be found using the periodic table.
- Plug in the values: moles = the number of moles in the 100 mL diluted solution (from the previous question) and molar mass = the molar mass of ASA.
- Solve for mass.
- The result will be in grams.

Determine the mass of ASA in 250 mL:
- Since you've already calculated the mass in the 100 mL diluted solution, you can simply use the proportion method to find the mass in 250 mL.
- Set up the proportion: mass in 100 mL / 100 mL = mass in 250 mL / 250 mL.
- Plug in the known values: mass in 100 mL (from the previous question) and solve for the mass in 250 mL.
- The result will be in grams.

Determine the % of ASA in the tablet:
- Divide the mass of ASA in the tablet (given in the question) by the mass of the tablet (also given in the question).
- Multiply the result by 100 to convert it to a percentage.
- The result will be the percentage of ASA in the tablet.

Determine the number of grains of ASA:
- The number of grains depends on the mass of ASA in the tablet and the mass of one grain of ASA.
- Divide the mass of ASA in the tablet by the mass of one grain of ASA to get the number of grains.
- The result will be the number of grains of ASA.