Question

32\. A student tries to determine experimentally the molar mass of aspirin (HAsp). She takes \(1.00 \mathrm{~g}\) of aspirin, dissolves it in water, and neutralizes it with \(17.6 \mathrm{~mL}\) of \(0.315 \mathrm{M} \mathrm{KOH}\). The equation for the reaction is $$ \mathrm{HAsp}(a q)+\mathrm{OH}^{-}(a q) \longrightarrow \mathrm{Asp}^{-}(a q)+\mathrm{H}_{2} \mathrm{O} $$ What is the molar mass of aspirin?

Short answer

Question: Based on the given information, determine the molar mass of aspirin. Answer: To calculate the molar mass of aspirin, follow these steps: 1. Calculate moles of OH- used: Moles of OH- = Molarity of KOH × Volume of KOH (in Liters) 2. Calculate moles of HAsp neutralized: Moles of HAsp = Moles of OH- 3. Calculate the molar mass of aspirin: Molar Mass of HAsp = Mass of HAsp / Moles of HAsp

Step-by-step solution

Calculate moles of OH- used

First, we need to calculate the moles of OH- ions used in the reaction. This can be done by using the volume and molarity of the KOH solution. Moles of OH- = Molarity of KOH × Volume of KOH (in Liters)

Calculate moles of HAsp neutralized

As per the reaction, one mole of HAsp reacts with one mole of OH-. Thus, the number of moles of HAsp neutralized is equal to the number of moles of OH- ions. Moles of HAsp = Moles of OH-

Calculate the molar mass of aspirin

Now that we have the moles of HAsp, we can calculate its molar mass using the given mass of aspirin (1.00 g). Molar Mass of HAsp = Mass of HAsp / Moles of HAsp