Which one among the following statements regarding the properties of mixtures and compounds is not correct?

Statement 4 is incorrect because it reverses the energy characteristics of mixtures and compounds. In a mixture, components are physically intermingled without chemical reactions, meaning no significant energy change (absorption or evolution) occurs during preparation [t1][t4]. Conversely, the formation of a compound involves a chemical reaction where elements combine in fixed ratios, typically resulting in the absorption or evolution of energy as new chemical bonds are formed [t1][t3]. Statements 1, 2, and 3 are correct: mixtures retain the properties of their constituents, whereas compounds exhibit entirely new properties [c1][c3][t2]. Mixtures can be homogeneous or heterogeneous, while compounds are always homogeneous pure substances [t1][t3]. Finally, the constituents of a mixture can be separated by physical methods like evaporation, but compounds require chemical means for separation [c3][t1][t2].

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 8: Nature of Matter: Elements, Compounds, and Mixtures > Snapshots > p. 130
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 8: Nature of Matter: Elements, Compounds, and Mixtures > 8.3.2 Compounds > p. 124