College Chemistry
posted by Jessica .
1) A 25mL sample of the .265M HCI solution from the previous question is
titrated with a solution of NaOH. 28.25mL of the NaOH solution is required
to titrate the HCl. Calculate the molarity of the NaOH solution.
2) A 1.12g sample of an unknown
monoprotic acid is titrated with 29.15mL of .315M NaOH. Calculate the molar mass of the acid.
3) A student dissolves a 1.18g aspirin tablet in water and titrates the
solution with a .265M NaOH. 22.05mL of NaOH are required to reach the
equivalence point. Calculate the percentage of acetylsalicylic acid in the tablet.

Wow,you are really wanting someone to do your homework for you. How many questions have you posted?!?!

yea this is to help not do all your work for u

The titration equation
Heqacid*Molarityacid*volumeacid=Heqbase*Molaritybase*volumebase
where Heqacid=1 for monoprotic acid, 2 for diprotic, and 3 for triprotic acid
Heqbase=1 for single OH, 2 for two OH, and 3 for three OH 
for your first question: first get a balanced equation, then calculate moles of HCl from that, then use the equation to get moles of NaOH and you use given information to get M NaOH

for your third question try using the equation (mass of acid/mass of tablet)x 100