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• Laboratory Safety Rules include wearing laboratory gowns, laboratory gloves, safety goggles, closed-toe shoes and long pants, and tied long hair (ladies).
• Chemical analysis is the measurement element in all of these examples and in many other cases.
• Feedback loop is the cycle of measurement, comparison, and control.
• Feedback system is the process of continuous measurement and control.
• Analytical results are incomplete without an estimate of their reliability.
• Safe, ethical handling of chemicals and wastes involves familiarizing yourself with safety features of your laboratory, no food and drinks allowed, use of contact lenses are not recommended, handling of organic solvents, concentrated acids, and concentrated ammonia should be done in a fume hood, cleaning up spills immediately to prevent accidental contact by the next person who comes along, treating spills on your skin first by flooding with water, knowing where to find and how to operate the emergency shower and eyewash, knowing how to operate the fire extinguisher and how to use an emergenc
• There are two types of materials: TC (To Contain) which hold liquids, and TD (To Deliver) which transfer liquids.
• The critical functions of a lab notebook are to state what you did and what you observed, it should be understandable by a stranger.
• Uncertainties in measurements can be represented as ± 0.2, with the lower the uncertainty, the better the accuracy.
• Computing analyte concentrations are based on the raw experimental data collected in the measurement step, the characteristics of the measurement instruments, and the stoichiometry of the analytical reaction.
• A desiccator is a closed chamber containing a drying agent called desiccant, for example, Silica gel.
• Reagents, precipitates, and glassware are conveniently dried in an oven at 110 degrees Celsius.
• Some chemicals require other temperatures for drying.
• The three most accurate tools for delivery (TD) are the burette, volumetric flask, and pipet.
• Calibration is done for greatest accuracy.
• Precipitates from gravimetric analyses are collected by filtration, washed, and then dried.
• A 0.03146 M aqueous solution prepared in winter when the lab temperature was 17 degrees Celsius has a molarity of 0.03146 M on a warm day when temperature is 25 degrees Celsius.
• Most precipitates are collected in a fritted-glass funnel (Gooch filter crucible).
• When using a syringe, take up and discard several volumes of liquid to wash the glass walls and to remove air bubbles from the barrel.
• Calibration is the process of measuring the actual quantity that corresponds to an indicated quantity on the scale of an instrument.
• Ideally, the measurement of the property is directly proportional to the concentration.
• The lid of a desiccator is greased to make an airtight seal, and desiccant is placed in the bottom beneath the perforated disk.
• To minimize contamination of dust particles during drying, use a beaker and watch glass.
• The molarity (M) of a solution is calculated by the formula M = moles / L.
• Liquid is contained in the disposable polypropylene tip of a serological pipet, which is stable to most aqueous solutions and many organic solvents except chloroform (CHCl3).
• Syringes come in sizes from 1 to 500 μL and have an accuracy and precision near 1%.
• Transfer pipets are calibrated to deliver one fixed volume and the last drop does not drain out of the pipet and should not be blown out.
• An analytical balance uses electromagnetic force compensation to balance the load on the pan.
• A buret is a precisely manufactured glass tube with graduations enabling you to measure the volume of liquid delivered through the stopcock (the valve) at the bottom.
• A volumetric flask is calibrated to contain a particular volume of solution at 20 degrees Celsius when the bottom of the meniscus is adjusted to the center of the mark on the neck of the flask.
• A buret is operated by washing it with new solution, eliminating air bubble before use, draining liquid slowly, delivering a fraction of a drop near end point, reading bottom of concave meniscus, estimating reading to 1/10 of a division, avoiding parallax, and accounting for graduation thickness in readings.
• The type of material to deliver (TD) in a buret is glass for acids and rubber for bases.
• An analytical balance is hypersensitive and can measure air and moisture, which affects the measurement.
• Types of burets include glass for acids and rubber for bases.
• Pipets and syringes are used to deliver known volumes of liquid.
• An analytical balance has a capacity of 100 – 200 g and a readability of 0.01 – 0.1 mg.
• Micropipets are used to deliver volumes of 1 to 1000 μL (1 μL = 10^-6 L).
• For analysis in the laboratory, the gross sample is usually reduced in size and homogenized to create the laboratory sample.
• Analytical Chemistry is a measurement science consisting of powerful ideas and methods that are useful in all fields of science and medicine.
• Analytical Chemistry deals with methods for determining the chemical composition of samples of matter.