Question

Find the correct statement about the solubility of a solution?
A. Gases decrease in solubility with an increase in temperature
B. $NaCl$ is insoluble in water
C. $Pb{I_2}$ is soluble in water
D. All nitrates are insoluble in water
F. Solubility depends solely upon the amount of solvent used

Answer 1

Solubility is the property of a substance which is measured as its ability to dissolve in solvent. Solubility of a substance depends on various factors besides the amount of solute and solvent.

Complete answer:
Let us evaluate the given statements regarding the solubility of a solution.
A. Gases decrease in solubility with an increase in temperature.
The given statement is correct. With increase in temperature the kinetic energy of the gas molecules increases. This results in an increase of randomness of the gas molecules dissolved in water. The attraction forces between the gas molecules decrease and they escape from the liquid phase to vapor phase.
B. $NaCl$ is insoluble in water
The given statement is incorrect. $NaCl$ is an inorganic salt composed of $N{a^ + }$ and $C{l^ - }$ ions. Nearly all sodium salts are soluble in water as the salts of sodium dissociate into ion in water and are solvated by water molecules. Hence $NaCl$ are soluble in water.
C. $Pb{I_2}$ is soluble in water
The given compound is and iodide salt of lead. According to the solubility rules, nearly all iodides are water soluble except lead, silver and mercury. $Pb{I_2}$ is however soluble in hot water. Thus the given statement is incorrect.
D. All nitrates are insoluble in water.
The given statement is incorrect. All the nitrates are soluble in water. Only the nitrate of silver i.e. silver nitrate is sparingly soluble in water.
E. Solubility depends solely upon the amount of solvent used.
The given statement is incorrect as the solubility of a substance not depends solely upon the amount of solvent but on other factors also. The factors include both the physical and chemical properties of the solute and solvent. Other factors like temperature, pressure and presence of other impurities also affect the solubility of the solution.

Note: The solubility of a solute can be decided on the measurement of ionic product and solubility product of a solute. Both of these are the product of the concentration of ions. The ionic product is the product of ion concentration when the ions completely dissociate in solution and the solubility product is the product when the ions are in equilibrium with the undissociated solutes in solution.