A-level Chemistry Revision Squad!

I know this is AS but really stuck any help/jints?
Direct titration

A student has read on a packet of aspirin that each tablet contains 250 mg of aspirin, and has decided to find out if this is true.

The systematic name of aspirin is 2-ethanoylhydroxybenzoic acid. Aspirin is a carboxylic acid and neutralises a cold dilute solution of sodium hydroxide to form a salt. This reaction is used to form the basis of a titration.

CH₃COOC₆H₄COOH + NaOH → CH₃COOC₆H₄COONa + H₂O

aspirin



1. Calculate the relative molecular mass of aspirin (2-ethanoylhydroxybenzoic acid). CALCUALTED 180 (1 mark)



The student decides to use this reaction in a titration to determine the mass of aspirin in each tablet.


She crushes four tablets, transfers them to a 100 cm³ volumetric flask, dissolving them in a 50:50 mixture of ethanol and distilled water (it is difficult to dissolve aspirin in pure water). Using a pipette she transfers 25 cm³ of this solution into a conical flask and titrates it against a 0.1 mol dm⁻³ standard solution of sodium hydroxide, using phenolphthalein as an indicator. The average titre is 14.70 cm³.



1. Calculate the mass of aspirin in each tablet. (4 marks)

Not sure where to start

Im sad that this thread is so inactive

Why?

Because exams are drawing closer but no one seems to post here. I mean if i get stuck now i just make a new thread. We're supposed to help each other out. The maths thread is always so active compared to this one.....

Can someone help me work out this questions cause i have no clue, thanks x

A 25.0cm3 sample of 0.0850 mol dm-3 hydrochloric acid was placed in a beaker. distilled water was added until the pH of the solution was 1.25. Calculate the volume of the solution formed. (3)