I am doing my chemistry practicle and my tecaher has told me that I need to standerise my 0.1moldm-3 solution of NaOH with HCl acid. But I don't know why or how, or what concentration of HCl. Does anyone have any ideas pls?
Why? NaOH pellets have no definite composition --- you can't make up solutions by weight to better than a few percent uncertainty, and, once made up, it's a base, it absorbs CO2 from the air --- so, no matter how careful you are about keeping it closed, the concentration changes over time. This much information is not as well stressed during instruction as it should be. You get this much for free.
Since this is more in the category of a HW problem, now, you can tell us what you do know, how much instruction you've had, what lab manual you're working from, how much success you had with the acid-base titration exercises, and what you think is the place to start on this problem. 'Kay?