Question

5. A sample of pure acetyl salicylic acid had a mass of 0.268 grams. It was dissolved in NaOH and diluted to 500.00mL in a volumetric flask.

a. What is the concentration of aspirin in the solution?
b. If an 8.00mL sample of this solution was pipetted into a volumetric flask and diluted to 100.00mL, what is the concentrated of aspirin after this dilution?

Answer 1

Answer:

a. 5.36x10⁻⁴ g/mL

b. 4.29x10⁻⁵ g/mL

Explanation:

As the units for concentration are not specified, I'll respond using g/mL.

a. We divide the sample mass by the final volume in order to calculate the concentration:

• 0.268 g / 500 mL = 5.36x10⁻⁴ g/mL

b. We can use C₁V₁=C₂V₂ for this question:

• 8.00 mL * 5.36x10⁻⁴ g/mL = C₂ * 100.00 mL

• C₂ = 4.29x10⁻⁵ g/mL