Question

In which of the following, sediment will not be observed on standing for some time? A. Chalk powder and water B. Copper sulphate and water C. Soil and water D. Fine sand and water​

Answer 1

B. copper sulphate and water

Answer 2

The correct solution is option B, Copper sulphate and water.

• When copper sulphate crystals are exposed to water, the particles of copper sulphate crystals lose their attraction to one another and begin to move around, mixing with the water. It's known as 'hydrated copper sulphate solution, and it's blue in colour. Due to this colour, it is also known as Blue Vitriol.
• Copper sulphate solubility is temperature-dependent, therefore raising the temperature stimulates more salts to dissolve, resulting in higher concentrations.
• Due to the hydration enthalpy generated during the dissolution, a little amount of heat energy is released in this process.
• When pure CuSO4 crystals are dissolved in H2O, the solvation enthalpy of H2O molecules exceeds the lattice enthalpy of the CuSO4 ionic solid. As a result, water molecules start to form a bridge between the Cu2+ and SO4 2– ions, a process known as dissolving in macroscopic terms. As a result, the ionic attraction between the cation (Cu 2+) and anion (SO4 2-) weakens with time, and the two ions separate.