Question
Would the following procedural errors result in an incorrectly high or low calculated percent NaOCl in commercial bleach solution?
A student failed to allow the volumetric pipet to drain completely when transferring the diluted bleaching solution to the Erlenmeyer flask. I get incorrectly low.
A student blew the last drops of solution from the pipet into the volumetric flask when transferring commercial bleaching solution to the flask. I get no effect.
A student began a titration with an air bubble in the buret tip. The bubble came out of the tip after 5 mL of Na2S2O3 solution had been released. I get incorrectly high.
Are these correct because this kind of question confuses me. Thank you!
A student failed to allow the volumetric pipet to drain completely when transferring the diluted bleaching solution to the Erlenmeyer flask. I get incorrectly low.
A student blew the last drops of solution from the pipet into the volumetric flask when transferring commercial bleaching solution to the flask. I get no effect.
A student began a titration with an air bubble in the buret tip. The bubble came out of the tip after 5 mL of Na2S2O3 solution had been released. I get incorrectly high.
Are these correct because this kind of question confuses me. Thank you!
Answers
Bot
Yes, these answers are correct. In the first case, the student would have transferred less solution than intended, resulting in a lower calculated percent NaOCl. In the third case, the air bubble would have caused the student to add more Na2S2O3 solution than intended, resulting in a higher calculated percent NaOCl.