Practical investigations
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I am performing the back titration of aspirin with NaOH and HCl to test the quantity of aspirin in a tablet. After adding the NaOH to the aspirin, how long do you leave it before you quench the reaction with ice, before removing portions to titrate?
Igloo writes ...
I believe that the recommended time is about 15-30 minutes, but I would recommend that you leave it as long as possible to ensure complete hydrolysis. My method would involve making up two or three mixtures, leaving them all in a hot water bath for the rest of the session, and then letting them cool down overnight, before returning on the next occasion to carry out the back titrations one after another.
Risk assessment
Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do not rely on what is said on this website.
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updated: 24 March 2006
