OAT General Chemistry Exam Guide with Complete Solutions

Accuracy - Answer-Refers to a measurement giving the actual value for a sample with a limited deviation; example: determining the weight of a sample to be 1g plus or minus 0.001g Precision - Answer-Repeatability of a set of measurements, and getting very close values to each other. Test tubes - Answer-small tubes that allow a large number of samples to be arrayed in a rack for easy processing. Beakers - Answer-Wide-mouthed cylinders with a lip to allow pouring Erlenmeyer flasks - Answer-container that is tapered at the top to avoid spills Round-bottom flasks - Answer-used for reaction, heating, or vacuum applications; spherical shape provides extra strength Retort - Answer-A round vacuum flask with a long neck that extends to the side; used for distillation Extraction flask/separatory funnel - Answer-teardrop shaped flask with a round glass stopper at the top and a stopcock at the bottom Transfer pipet - Answer-Often made of plastic and have an integral bulb at the top Pasteur pipet - Answer-Often made of glass with a long tapered tip and require a separate rubber pipet bulb Graduated cylinder - Answer-a tall, narrow tube with volume markings with a lip at the top for pouring Buret - Answer-a long tube that is clamped in place vertically with a stopcock at the bottom; the amount delivered is determined by the difference between the starting volume and the final volume in the buret; used for titrations Graduated pipet - Answer-a hand-held and controlled by a pipet bulb that maintains a slight vacuum Volumetric pipet - Answer-have a large bulge in the middle of the tube and deliver a single established volume of liquid with great accuracy and precision