In general, pipets are used to measure and transport very precise volumes of liquids between containers or solutions. The term micropipet is used to describe a pipette that is used to work with very small volumes, less than 1000 ul (1 ml). Research assistants, scientists, and medical laboratory workers are just some of the professionals that utilize pipets in their laboratories.
There are almost countless makes and models of micropipets. Some of the functional features that may differ between models include volume range, incremental units, mode of operation (electronic or mechanical), autoclavability, and various ergonomic design features. To choose a model that is best for your laboratory and the proposed activity it is important to consider these features.
Continue reading ‘Proper Use and Features of Micropipets’
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Purpose
To illustrate the various oxidation states of an element.
Materials
- Potassium permanganate, KMnO4 (0.1 M)
- Sodium hydroxide, NaOH (2.0 M)
- Sulfuric acid, H2SO4 (3.0 M)
- Sodium bisulfite, NaHSO3 (0.1 M)
- EDTA (1.0 M)
- Manganese(II) sulfate, MnSO4 (powder)
- 5 ea. 100 mL beakers
- 50 mL graduated cylinder
Safety
- Read the MSDS/WHMIS sheets for all chemicals before using them
- Wear chemical safety glasses, gloves, and lab coat
- Concentrated acids and bases are used
- Permanganate solution will stain
Continue reading ‘Colors of Manganese Ions ScholAR Demonstration’
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ScholAR Chemistry has provided a useful reference guide for school laboratories. Information in the guide includes:
- cleaning and sterilizing glassware
- cleaning microscopes
- pH Defined
- making a buffering solution
- preparing molar & normal solutions
- dilution table for liquids
- useful reagents
- common preservatives and fixatives
- general stains
- Centigrade - Fahrenheit conversions
- Mohs’ Scale of Hardness
- weight, length and volume conversions
- table of atomic symbols, numbers and weights
Most of the reference material is included below for quick, easy access. However, conversion charts and other large tables are available in the PDF file linked below:
Ward’s ScholAR Lab Reference Guide (PDF, 60 kb)
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Purpose
To illustrate a combustion reaction involving a solution with a low combustion temperature.
Materials
- Paper ($20.00 bill or piece of white paper towel)
- Isopropyl alcohol, 99%
- 1 ea. 400 mL beaker
- Crucible tongs
- Container of water (to extinguish the burning paper)
Safety
- Read the MSDS/WHMIS sheets for all chemicals before using them
- Wear chemical safety glasses, and lab coat
- Alcohol is highly volatile and flammable, ensure no open flames are present (candle, Bunsen burner)
- Avoid inhalation of alcohol vapors
- Burning drops of alcohol may fall from the bill so ensure the audience is at least 1 meter away
Continue reading ‘Burning Money ScholAR Demonstration’
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Purpose
To develop a model of a redox reaction where oxygen gas is the oxidizing agent.
Materials
Safety
- Read the MSDS/WHMIS sheets for all chemicals before using them
- Wear chemical safety glasses, gloves, and lab coat
- Sodium hydroxide is caustic, handle with care
Continue reading ‘Blue Bottle ScholAR Demonstration’
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The annual Orionid Meteor Shower will provide another fine display of celestial fireworks for skywatchers during the early morning hours of October 21st. The window of opportunity for having a dark sky in which to see these “shooting stars” occurs soon after the 9-day-old Moon goes down around 1:30 a.m. EDT and before the Sun comes up. So plan to head to bed early the night before and set your alarm accordingly; losing some sleep to get up in the wee hours for a meteor watch will definitely be well worth it!
Given clear skies on the morning of October 21st, observers will be treated to one of the year’s most reliable displays of shooting stars — the Orionids. Peak activity occurs around 5 a.m. EDT, with as many as 25 meteors an hour being visible under good conditions. While not one of the richer showers, it’s radiant (the point from which the meteors appear to “shoot”) is located in a glorious part of the heavens — that of magnificent Orion! The actual point lies between Betelgeuse in the Hunter’s shoulder and (this year) nearby Mars, with both sentries glowing a brilliant ruddy-orange in hue.
Continue reading ‘The Orionid Meteor Shower’
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An asterism is a distinctive pattern of stars lying within a constellation–or, in some cases, one made up of stars from two or more adjoining constellations. Undoubtedly, the best-known and most easily recognized of all such grouping is the Big Dipper in the constellation of Ursa Major. But each of the four seasons of the year has its own starry asterism, which are not only fascinating in themselves but also make it easy to find your way around the night sky. The guidepost for Fall is that known as the Great Square of Pegasus, located high in the southeastern sky during October. (Those of the other three seasons will be featured in future installments.)
Continue reading ‘Fall’s Great Square Asterism’
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One of the great icons of our times is the word “galaxy,” which appears in the news media and on the Internet almost daily. Most of these majestic denizens of deep space require a telescope to be seen since they lie many millions and even billions of light-years away. But there’s at least one that requires no optical aid to see, being strikingly visible to the unaided eye on a dark clear night — and that’s the galaxy we live in! We’re referring, of course, to the Milky Way.
Continue reading ‘The Milky Way Galaxy’
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