Describe the correct technique for reading the meniscus of a solution in the buret.

Answer 1

Align the eye EXACTLY in line with the bottom of the meniscus (to avoid parallax) and read the bottom of the meniscus. I use my finger placed just below the meniscus on the outside of the buret so that my finger image is reflected off the bottom of the meniscus. That allows me to read the very bottom of the meniscus with almost no error every time. My students always had trouble with that technique and many of them used a black marker pen to blacken a square area on a 3 x 5 card, cut two slits about 1" apart in the card and slip the card over the buret so that the blackened ares is BEHIND the meniscus in the buret. Then sliding the card up or down that blackened area can be placed directly behind the meniscus which makes it easier to read. Note that some liquids, particularly KMnO4, can't be read on the bottom of the meniscus in which case some part above the meniscus must be read and what ever place you pick should be easy to duplicate.