Chemistry Notes

Learn chemistry. Here you will find a collection of chemistry notes, projects, worksheets, and labs.

Sulfuric acid is an example of a diprotic acid. — A diprotic acid is an acid that can donate two hydrogen ions (H+) or protons per molecule in an aqueous solution. Another name for a diprotic acid is a dibasic acid. A diprotic acid is a type of polyprotic acid, which is an acid able to donate more than one […]

Diprotic Acid Definition and Examples Recently updated !

This entry was posted on March 23, 2020 by Anne Helmenstine (updated on March 23, 2020)

Intensive and extensive properties of matter are distinguished by whether the amount of matter changes the property. — Intensive and extensive properties are the two classes of physical properties of matter. A physical property, in turn, is one which can be observed and measured without changing the chemical composition of the sample. Physical chemist and physicist Richard C. Tolman coined the terms “intensive” and “extensive” in 1917. Here […]

Difference Between Intensive and Extensive Properties of Matter

This entry was posted on March 18, 2020 by Anne Helmenstine (updated on March 18, 2020)

You can't use pH paper to measure negative pH. — Have you ever wondered whether a negative pH value is possible in chemistry? The answer is yes! The pH scale usually runs from 0 to 14, but if the molarity of hydrogen ions in a strong acid is greater than one you’ll calculate a negative pH value. For example, the […]

Is Negative pH Possible? How It Works and Where to ...

This entry was posted on March 16, 2020 by Anne Helmenstine (updated on March 16, 2020)

Cation and Anion Difference — Cations and anions are the two types of ions. Ions have an imbalance of electrical charge, meaning they contain different numbers of protons and electrons. Cation have a positive electrical charge and have more protons than electrons. Anions have a negative electrical charge and have more electrons than protons. Neutrons […]

Cations and Anions: Definitions, Examples, and Differences

This entry was posted on March 3, 2020 by Anne Helmenstine (updated on March 3, 2020)

Hydrofluoric Acid (HF) Molecule — Hydrofluoric acid or HF is an extremely powerful, corrosive acid. However, it’s classified as a weak acid rather than a strong acid. This makes HF the only hydrohalic acid that isn’t classified as a strong acid (e.g., HCl, HBr, HI). Why Hydrofluoric Acid Is a Weak Acid The simple reason […]

Is Hydrofluoric Acid a Strong or Weak Acid?

This entry was posted on March 1, 2020 by Anne Helmenstine (updated on March 1, 2020)

Strong and Weak Acids — Strong and weak acids are key concepts in chemistry. Strong acids completely dissociate into their ions in water, while weak acids incompletely dissociate. There are only a few strong acids, but many weak acids. Strong Acids Strong acids completely dissociate in water into their ions and produce one of more […]

List of Common Strong and Weak Acids

This entry was posted on February 28, 2020 by Anne Helmenstine (updated on February 28, 2020)