Volumetric pipets & flasks, burets, and graduated cylinders all have markings (lines) etched into the glassware denoting volume levels. Correctly recording the volumes from these pieces of glassware incorporates the following four concepts:
1. Meniscus: The meniscus is the \__________ of the liquid surface in the glassware. If the liquid contained in the glassware is polar, adhesion \__________ cohesion. leading to a \__________ meniscus. If the liquid is nonpolar, adhesion is \__________ cohesion, leading to a \__________ meniscus.
(first blank)
A. tension
B. polarity
C. level
D. curvature
(second + fourth blank)
A. less than
B. equal to
C. greater than
(third blank)
A. convex
B. concave
\__________________________________________
2. Parallax error: To avoid parallax error, you must have your eyes level to the \__________.
A. center of your goggles
B. middle of the glassware
C. benchtop
D. top or bottom of the meniscus
\__________________________________________
3. Significant Figures: The number of digits used when recording the volume from each piece of glassware is determined by the \_________ for burets and graduated cylinders and by \__________ for volumetric pipets and flasks.
A. numbers from markings + a last number estimated between markings
B. glassware's total volume
C. information provided in the course material
D. etched value on glassware (+/1 0.05 mL)
\__________________________________________
4. Temperature: The temperature of the liquid held by the glassware \__________ affect volume measurements, therefore, all liquids should be at \__________.
(first blank)
A. does not
B. does
(second blank)
A. 0 Celsius
B. 273 K
C. the liquid's boiling point
D. room temperature