Tiêu đề Volumetric analysis iswori.com.np .pdf ✅

Volumetric analysis Volumetric analysis is defined as the process of the determination of concentration of unknown solution by finding its volume which will exactly react with a definite volume of another solution of known concentration. Gravimetric analysis is defined as the process of quantitative determination of an analyte(the ion being analyzed) based on mass of solid. At first solution of given sample is prepared, treated with suitable reagent to convert into insoluble form which is made pure by washing, dried and weighed. Then the weight of the required substance is calculated with the help of theoretical concept. 1

Pre-requirements in volumetric analysis Equivalent weight (equivalent mass) It is defined as “the no. of parts by wt. of the substance that combines with or displaces 1.008 parts by wt. of hydrogen, 8 parts by wt. of oxygen or 35.5 parts by wt. of chlorine.” Equivalent weight is unit less. Equivalent weight expressed in gm. is called gm. equivalent. No. of gm. eqvt. = given wt./eq.wt. 3
Relation between equivalent weight, atomic weight and valency Let the atomic weight, equivalent weight and valency of an element be A, E and V respectively. From the definition of valency, V atoms of Hydrogen combines with 1 atom of the element. V x 1.008 part by wt. of H combines with A part by wt. of the element. 1.008 part by wt. of H combines with A/V part by wt. of the element. So, eq. wt. of the element = A/V or, E = A/V The nature of chemical change decides the equivalent wt. of a substance. The equivalent weight is not a constant quantity. The equivalent wt. of different substances are calculated as follows: 4