if we tritrate weak acid(oxalic acid)with strong base(naoh).which indicator is used and why

2 answers

Your School SUBJECT is CHEMISTRY.
The titration of a weak acid and strong base gives a pH at the equivalence point of between 8 and 10. The k1 for oxalic acid is fairly strong but hard to separate from k2. So you want an indicator that will change about 8-10. Phenolphthalein is suitable for that.