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EQWstands forEquivalent Weight
Full Form of EQW
What is EQW?
Equivalent weight (EQW) is a fundamental concept in chemistry, defined as the mass of a substance that combines with or displaces one mole of hydrogen atoms (or the equivalent amount of another reagent) in a chemical reaction. It is widely used in volumetric analysis, particularly in titration calculations involving normality. In the Indian education system, equivalent weight is a core topic in Class 11 and 12 chemistry curricula, and it appears frequently in competitive exams such as JEE Main, JEE Advanced, NEET, and state-level engineering and medical entrance tests. Students learn to derive EQW for acids (molar mass divided by basicity), bases (molar mass divided by acidity), and salts (molar mass divided by total positive or negative charge). The concept also extends to redox reactions, where EQW is molar mass divided by change in oxidation number. Understanding equivalent weight is essential for solving problems related to concentration, dilution, and stoichiometry. In laboratories, EQW helps standardize solutions and ensures accurate experimental results. Despite the increasing use of molarity in modern chemistry, equivalent weight remains relevant for certain industrial processes and analytical methods. For Indian exam aspirants, mastering EQW calculations can directly improve scores in chemistry sections, making it a high-yield topic for preparation.
EQW का फुल फॉर्म
समतुल्य भार
Example
In the JEE chemistry problem, we needed to find the equivalent weight of KMnO₄ in acidic medium, which is 31.6 g/eq.
EQW — frequently asked questions
What is the full form of EQW?
EQW stands for Equivalent Weight, a chemical property representing the mass of a substance that reacts with one mole of hydrogen ions or electrons.
How is equivalent weight calculated for an acid?
For an acid, equivalent weight is calculated by dividing its molar mass by the number of replaceable hydrogen ions (basicity). For example, H₂SO₄ has a molar mass of 98 g/mol and basicity 2, so EQW = 98/2 = 49 g/eq.
Why is equivalent weight important for Indian competitive exams?
Equivalent weight is frequently tested in JEE Main, JEE Advanced, NEET, and other entrance exams through numerical problems on normality, titration, and stoichiometry, making it a crucial concept for scoring marks.