2. Acetylacid (ASA) is an active component of aspirin tablets which are commonly used as pain
relievers for headaches. the molecular formula of ASA is C9H804
a. What is the molar mass of acetyl salicylic acid ?
b. What is the percentage of carbon in acetyl salicylic acid?
c. How many grams of carbon are there in 25 g of acetyl salicylic acid?
d. If a person needs 50g of ASA to relieve his headache, but the available medicine tablets are in 25 g SA dose,
can he take more than one tablet at once ? why? or why not?

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :