Sulfuric acid titration is the process of finding the molarity of a basic solution using sulfuric acid as a titrant. The titrant, which is a substance whose concentration is known exactly, is added to a solution of unknown concentration until a reaction fully takes place. This can be measures using a chemical indicator or a pH indicator. A calculation can then be performed based on the known concentration of the titrant and the amount of the titrant needed to neutralize the unknown substance. This calculation allows scientists to determine the molarity, or chemical weight, of the unknown substance.
The first step in understanding sulfuric acid titration is to grasp the concept of a mole. In chemistry, a mole of any given substance is the gram equivalent of its mass number. The mass number is the total weight of the element or compound, so for carbon-12, the mass number is 12. This means that one mole of carbon-12 weighs 12 grams. Moles are used as a method of measuring the amounts of certain chemicals within reactions.
Acids and bases react with each other to produce water and a salt. A base is a substance with a pH of between 8 and 14, and an acid is a substance with a pH of between 1 and 6. The neutral point on the pH scale is 7, which means that the solution is neither acidic nor basic. If equal amounts of a pH 1 acid and a pH 14 base are mixed together, the resulting solution will have a pH of 7. This reaction takes place during sulfuric acid titration.
Each substance in sulfuric acid titration is in an aqueous form, meaning that it is dissolved in water. The sulfuric acid, being the titrant with a known molar value, is of a certain concentration within the water. The other substance, for example sodium hydroxide, is in an aqueous solution but the amount of it within the solution is not known. Chemical reactions are very efficient, in that no substances are lost when they take place. When sulfuric acid reacts with sodium hydroxide, it produces water and sodium sulfate.
The process of sulfuric acid titration involves placing a certain amount of the unknown solution in a beaker and a certain amount of sulfuric acid in a buret, a device for adding specific amounts of substances to other substances. Acid is added to the basic solution until the pH meter reads 7, meaning that the base has neutralized. The amount of sulfuric acid added to the solution at this point is equal to the amount of the basic substance present in the solution of unknown molarity. Chemists then calculate the specific molar amount of the unknown solution based on the known values.