Solid Solute and Normality

To determine the weight of a solid that is needed to prepare a solution of a given normality, we can derive an equation in a manner similar to that in Section 4.4.1 for molarity  

As in Section 4.3, acid-base neutralization reactions will be illustrated here. In order to calculate the equivalent weight of an acid, the balanced equation representing the reaction in which the solution is to be used is needed so that the number of hydrogens lost per formula in the reaction can be determined. The equivalent weight of an acid is the formula weight of the acid divided by the number of hydrogens lost per molecule (see Section 4.3). 

How many grams of KH2P04 are needed to prepare 500.0 mL of a 0.200 N solution if it is to be used as in the following reaction  

There are two hydrogens lost per formula of KH2P04. Therefore the equivalent weight of KH2P04 is the formula weight divided by 2. Utilizing Equation (4.13), we have the following  

---