Basic Chemistry
In chemistry, “normal value” might refer to several different concepts depending on the context:
- Normality (N): Normality is a concentration unit used in chemistry to express the concentration of a solution. It is defined as the number of equivalents of a solute dissolved in one liter of solution. For example, a 1 Molar (1M) solution of hydrochloric acid (HCl) would be equivalent to a 1 Normal (1N) solution because HCl is a monoprotic acid and thus has one equivalent per mole.
- Standard Conditions: In chemistry, standard conditions often refer to a set of conditions defined for experimental measurements, such as temperature and pressure. For example, standard temperature and pressure (STP) are defined as 0 degrees Celsius and 1 atmosphere pressure. These values are used as reference points for comparing experimental data.
- Reference Values for Properties: In chemical analysis, there are often established normal or reference values for various properties such as melting point, boiling point, density, etc., for specific substances under standard conditions. Deviations from these values can indicate impurities or changes in the substance’s composition.
- Electrochemical Potential: In electrochemistry, normal hydrogen electrode (NHE) is often used as a reference electrode to measure the electrochemical potential of other electrodes. The potential of the NHE under standard conditions (1 atm H2 gas, 1 M H+ ions) is defined as 0 volts.