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need assistance with part b thanks (1 Viewer)

Run hard@thehsc

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B) its a weak acid, hence does not completely dissociate. As such, it is close to impossible to deduce the amount of NaOH needed to neutralise ethanoic acid and hence produce the endpoint (i.e. the H+ would be the partially ionised ones, and as such, all the OH- that reacts with this H+, will not equal the change in endpoint). Most likely, this will produce an endpoint quicker than what is required. Therefore, pH tests are more effective as they can deduce between acid strength and concentration as well (pH = -log H+)...
 

someth1ng

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B) its a weak acid, hence does not completely dissociate.
Correct.

As such, it is close to impossible to deduce the amount of NaOH needed to neutralise ethanoic acid and hence produce the endpoint (i.e. the H+ would be the partially ionised ones, and as such, all the OH- that reacts with this H+, will not equal the change in endpoint).
You can titrate ethanoic acid and sodium hydroxide (i.e. question is just...wrong). The weak acid is in dynamic equilibrium, so as you neutralize with NaOH, more H+ will be made until all acid has become sodium acetate. NaOH and acetic acid will give an equivalence point at pH ~9 (depending on concentration etc). HCl and NaOH will give an equivalence point closer to 7. If you plot the titration, neutralisation of acetic acid and HCl will look very different (inflection point at different pH levels).

If you have two solutions of similar concentration, then yes, measuring pH alone will work. However, it's possible to have an acetic acid solution and HCl solution with the same pH (and different concentrations).
 

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