An acid, according to the Arrhenius definition, is a substance that, when dissolved in water, increases the concentration of hydrogen ions (H+) in the solution. A base, on the other hand, is a substance that, when dissolved in water, increases the concentration of hydroxide ions (OH-) in the solution.

Acid: HA (substance) + H2O → H3O+ (hydronium ion) + A- (conjugate base)

Base: B (substance) + H2O → BH+ (conjugate acid) + OH- (hydroxide ion)

Acid-Base Reaction

When an acid and a base react, the H+ ions from the acid combine with the OH- ions from the base to form water molecules (H2O). This process is called neutralization. The products of a neutralization reaction are a salt (a compound composed of positively charged ions and negatively charged ions) and water.

Arrhenius Acid-Base Reaction: Acid (H+ donor) + Base (OH- donor) → Salt + Water (H2O)

Here is a general example of an acid-base reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH):

- Reactants: HCl (acid) + NaOH (base)

- Products: NaCl (salt) + H2O (water)

The reaction can be represented as follows:

HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)

In this reaction, the H+ ions from the HCl combine with the OH- ions from the NaOH to form water molecules (H2O). The remaining ions (Na+ and Cl-) combine to form the salt sodium chloride (NaCl).