Acids and bases

 Acids and bases are common chemicals. Acids release H⁺ ions when in water, and bases release OH⁻ ions when in water. Acids can react with bases. The H⁺ ion is taken from the acid by the base. This makes water, H₂O. A salt is also made when an acid and a base react together. An example would be reacting hydrochloric acid (HCl) and sodium hydroxide (NaOH). Hydrochloric acid releases H⁺ and Cl^- ions in water. The base releases Na⁺ and OH^- ions. The H⁺ and the OH^- react to make water. There is a solution of sodium chloride (NaCl) left. Sodium chloride is a salt.

An acid is a substance that can donate a hydrogen ion (H⁺) (generally speaking, this will be a proton) to another substance. Acids have a pH less than 7.0. A chemical can donate a proton if the hydrogen atom is attached to an electronegative atom like oxygen, nitrogen, or chlorine. Some acids are strong and others are weak. The weak acids hold on to some of their protons, while the strong acids let go of all of them. All acids will release hydrogen ions into solutions. The amount of ions that get released per molecule will determine if the acid is weak or strong. Weak acids are acids that partially release the hydrogen atoms that are attached. These acids, then, may lower pH by dissociation of hydrogen ions, but not completely. Weak acids generally have a pH value of 4-6 while strong acids have a pH value of 1 to 3.

A base is an acid's "chemical opposite." A base is a substance that will accept the acid's hydrogen atom. Bases are molecules that can split apart in water and release hydroxide ions.

Acids can have different strengths, some are more reactive than others. More reactive acids are often more dangerous.

Acids can have a lot of different properties depending on their molecular structure. Most acids have the following properties:

• taste sour when they are eaten
• can sting the skin when they are touched
• can corrode (or eat away at) metals and skin
• can be used as a reactant during electrolysis due to the presence of mobile ions
• turn blue litmus paper red
• turn red or orange on universal indicator
• conduct electricity

Acids can burn the skin, the severity of the burn depending on the type and concentration of the acid. These chemical burns require immediate medical attention.

Because acids donate hydrogen ions, all acids must have hydrogen in them.

Acids can have different strengths, some are more reactive than others. More reactive acids are often more dangerous.

Acids can have a lot of different properties depending on their molecular structure. Most acids have the following properties:

• taste sour when they are eaten
• can sting the skin when they are touched
• can corrode (or eat away at) metals and skin
• can be used as a reactant during electrolysis due to the presence of mobile ions
• turn blue litmus paper red
• turn red or orange on universal indicator
• conduct electricity

Acids can burn the skin, the severity of the burn depending on the type and concentration of the acid. These chemical burns require immediate medical attention.

Because acids donate hydrogen ions, all acids must have hydrogen in them.