Laboratory

Natural ammonium nitrate is called niter. It is analogous to saltpeter, which is natural potassium nitrate. (Ben Mills) — Ammonium nitrate is a chemical compound used in agriculture and to make pyrotechnics or cold packs or to perform other interesting demonstrations. It’s also used to create controlled explosions in mining and quarrying. It was once mined as a natural mineral in the deserts of Chile, but it is no […]

How to Make Ammonium Nitrate From Household Chemicals

This entry was posted on January 8, 2018 by Anne Helmenstine (updated on January 8, 2018)

Graduated Cylinder (Gordon) — It’s often necessary to dry or pre-rinse a graduated cylinder for use in chemistry lab. When you wash or dispense liquid from a graduated cylinder, a small amount of liquid remains. This liquid can have an adverse effect on your results, so you may need to either pre-rinse the cylinder […]

How to Dry or Pre-Rinse a Graduated Cylinder

This entry was posted on September 18, 2017 by Anne Helmenstine (updated on September 26, 2017)

Qualitative data describes, while quantitative data is expressed using numbers. (dirkcuys) — There are two types of data. Qualitative data is descriptive information about characteristics that are difficult to define or measure or cannot be expressed numerically. Quantitative data is numerical information that can be measured or counted. Qualitative → Qualities Quantitative → Quantities Examples of Qualitative Data feelings and emotions texture […]

Qualitative and Quantitative Data – Definitions and Examples

This entry was posted on March 27, 2017 by Anne Helmenstine

Vodka is used for science experiments because it is a relatively inexpensive form of ethanol in water. (photo credit: Andrew Cheal) — I’m commonly asked why many chemistry ‘recipes’ call for vodka or Everclear as opposed to medical-grade ethanol (alcohol). The answer is simple: It’s easy and inexpensive to obtain vodka, while obtaining medical-grade ethanol, even if you have a permit, can be expensive. Aside from the regulations surrounding ethanol, it’s a […]

Why People Use Vodka for Science Experiments

This entry was posted on August 30, 2015 by Anne Helmenstine

Do you have any lab accident horror stories? (Clinton Steeds) — Do you have any tales to tell of lab experiments gone very wrong or lab accidents you have witnessed? What is the most dangerous thing you have ever seen someone do in a lab? Here’s your chance to tell the tale. A Freshman in Regents Chem I was cleaning the […]

True Lab Accident Horror Stories

This entry was posted on July 3, 2015 by Anne Helmenstine (updated on April 15, 2018)

Nitrile Glove — One of the most common materials used to make disposable gloves is nitrile. Nitrile compounds contain the CN- (cyano) functional group. Nitrile gloves are available in many colors, though the most common colors are purple and blue. There are a couple of interesting facts about these gloves: You either want […]

Interesting Facts About Nitrile Gloves

This entry was posted on July 19, 2014 by Anne Helmenstine (updated on July 19, 2014)