Laboratory

Saline solution is made by dissolving sodium chloride into water. — Saline solution is a solution of salt (sodium chloride) in water. While it’s commercially available, saline solution is easy to make yourself, using nothing more complicated than salt and water. Use the Right Salt and Water If you’re making saline solution to soak sore muscles or as a mouth rinse, […]

How to Make Saline Solution

This entry was posted on August 17, 2018 by Anne Helmenstine (updated on September 1, 2018)

Aqua Regia Solutions (Thejohnnler) — Aqua regia is a highly corrosive mixture of hydrochloric acid (HCl) and nitric acid (HNO3) in a molar ratio of 3:1 or 4:1. The name “aqua regia” translates from Latin to mean “king’s water” or “royal water,” referring to the acid’s ability to dissolve the noble metals gold, platinum, and […]

Aqua Regia Definition and Preparation Recently updated !

This entry was posted on August 16, 2018 by Anne Helmenstine (updated on October 13, 2018)

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