Chem 104 Lab Exam A+ 2024

Common Lab Equipment - Correct Answer Vial and cap Test tube Test tube holder Glass stirring rod Test tube brush Watch Glass Pipet Pasteur Pipet Pasteur Pipet rubber bulb Spatula Weigh boat Graduated cylinder Beaker Buret Wash Bottle Erlenmeyer Flask Retort Stand (Buret clamp, Utility clamp, Ring Clamp) Vacuum Flask Round Bottom Flask 9 well glass plate Buchner funnel funnel seal How to tell if glassware is clean - Correct Answer glass wets uniformly if the meniscus pulls away from the side as it drains, it is not clean How to clean glassware - Correct Answer scrub with a brush using soap and tap water, then rinse with deionized water to prevent hard water deposits Drying Glassware - Correct Answer No paper towel, air dry. If you are not done using it, rinse with the solution you plan on using a couple times Working with reagents - Correct Answer 1. take only the min reagent from stoke bottle 2. liquid reagents in clean test tube, flask or beaker. solid in watch glass or small beaker 3. never dip pipet into stock bottle 4. never return reagent to stock bottle 5. stopper reagent bottles after use Significant figures - Correct Answer exact numbers -infinite significant significant - non-zero, zeroes between non zeroes, trailing zeroes to left and right of decimal place not significant - leading zeroes, trailing zeroes w/o decimal place[ambiguous format, avoid] **Leave two numbers in trailing subscript (not significant)