In the field of Chemistry, we often come across many a kind of process and what we actually look forward is that we need to understand as to how the different chemicals will perform and what are the different measures that are to be implemented as well.
Normality in chemistry is defined as one of the expressions that arebeing used to measure the concentration of a solution. The usual way that it is being denoted is ‘N’ and in most of the cases it can be referred to as the equivalent concentration of a solution. This concept is being mainly used as a measure of reactive species that are being put in a solution and also to learn the process during the titration reactions or particularly in situations involving acid-base chemistry.
If we are to go with the standard definition, then normality is described as the number of gram or mole that will be equivalent of solute that is present in one liter of a solution. When we say equivalent, it means that we are speaking about the number of moles in the compound as well.
There are however certain points that are to be listed so that we will be able to understand the mechanism that may be required for the calculation as well.
- Normality unit is denoted by N or eel/L .the parameter will depend on the chemical reaction that is being studied and will also depend on temperature too. So we can say that the chemical reaction will have a set pattern as well.
- The reaction levels will depend on the reactive capacity of the solution and so it is called equivalent concentration
- The concept of normality is mostly being used in acid-base reactions and redox reactions
Normality Formula
There are different formats and the ways in which this normality formula is being put into application. Few of the important formulas that are being used frequently are given below:
- Normality = Number of gram equivalents × [volume of solution in liters]-1
- Number of gram equivalents = weight of solute × [Equivalent weight of solute]-1
- N = Weight of Solute (gram) × [Equivalent weight × Volume (L)]
- N = Molarity × Molar mass × [Equivalent mass]-1
- N = Molarity × Basicity = Molarity × Acidity
As we always know that normality is often denoted by N. However, we will have some of the units of normalitythat are also expressed as eel L-1 or me L-1. This is important to note that the latter notifications are often used in medical applications only.
How to Calculate Normality?
There are certain tips that can help the students to calculate the normality issue with ease. Let us have a look at that:
- The first tip that is usually advised to the students is that they can gather information about the equivalent weight of the reacting substance or the solute this they can do by learning the concepts in the textbooks and understanding the valence bonding as well.
- The second step that is involved in the process is that we will be calculating the no. of gram equivalent of solute in the chemical reaction.
- The most important thing to remember here is that the volume is to be calculated in liters.
- Finally, we should note that while calculating normality we will be using the formula and replacing the values.
Potential Issues Using N for Concentration
One of the important things that we should note here is that though this is considered as a useful unit of concentration, but it can’t be used for all situations because the value depends on an equivalence factor that can change based on the type of chemical reaction that is taken into account.
For example, a solution of magnesium chloride (MgCl2) might be 1 N for the Mg2+ ion, but at the same time it may have 2 N for the Cal– ion.
In the similar manner, N is considered a good unit to know, it’s not used that much in case of as molality as in actual lab work. It always has the value for acid-base titrations, precipitation reactions, and redox reactions. However, in case of the acid-base reactions and precipitation reactions, 1/few are an integer value and so in case of redox reactions, 1/few it might be a fraction.