posted by ? on .
4.00 g dm^-3 of impure sodium carbonate is used in a titration. What could have caused the impurity in the sodium carbonate?
Isn't this a wide open question? I might add far wide open question. Any number of about 1 million things. There is no way to answer a question like this. Would you like to put some limits on it. I could still be writing this time next year.
Haha, it says find out what could have caused the impurity in the sodium carbonate. Isn't this to do with before the titration so could I say that a substance could have contaminated it?
If you think that is the point of the question, yes. But if that is the point, the question may be related to how the Na2CO3 is prepared for sale to laboratories. Na2CO3 is a good primary standard to use for acid/base titrations; however, my experience is that we don't trust Na2CO3 in a bottle. We make our own by heating NaHCO3 at moderately low heat (I think it's about 300 C). So the answer your prof may be looking for is that the Na2CO3 in the bottle could be a mixture of the decahydrate and the monohydrate (and/or other intermediate hydrates). Hope this helps.
Yes it helps alot, many thanks!
1)What could have caused the impurity in the sodium hydroxide solution...
2)Why was it necessary to dilute the hydrochloric acid before carrying out the titration
This was a question from a titration practical in which we had to dilute HCL then use that along with 25cm3 of NaOH to find out the %purity of NaOh