CaCl2 is another water-soluble salt. Let\'s compare the solubilities of NaCl and
ID: 559108 • Letter: C
Question
CaCl2 is another water-soluble salt. Let's compare the solubilities of NaCl and CaCh2 using the given PEC diagrams. Evaluate the following statements about the water-solubility of the two electrolytes. caaes) Sol ble a zoom A The solubility of NaCI is favored by potentially, while, the number of configurations favors the solubility of CaCl 8) The solubility of CaCl2 is favored by potentially, while, the number of configurations favors the solubility of Naci. c The ion-dipole interactions between the Ca2 ions and water molecules are stronger than the ion-dipole interactions between the Na" ions D The lower number of configurations in the dissolved state of CaCl2 is due to the greater organization of water molecules around the Ca2 E The solubility of both CaC2 and NaCI will increase as the temperature is increased. and the water molecules due to greater charge on the Ca2 ions. ions resulted by its high charge (+2) compared to Na+ ions.Explanation / Answer
As we know NaCl and CaCl2 bothe are solble in water and they both are used as salts in food. The bond strength depends on the lattice energy. When there is small size of cation then the lattice energy would be more, as the inter-ionic distance is less. When we go down the group then the lattice energy decreases as the cation size increases. More the lattice energy more stable is ionic compund.
In our case, NaCl has lattice energy of -788 KJ and for CaCl2 lattice energy is -2255KJ.
Smaller size ions require less energy to get hydrated. For the molecule to get hydrated, hydration energy must be more than lattice energy. As we can see from the PEC diagram of NaCl, molecules of Na+ get easily hydrated because of small size of cation than anion. But in case of Ca2+ ion , the size of cation is bigger than anion, so to break this molecule we require more energy.
When dissolved in water, CaCl2 releases -66 KJ of energy in water and NaCl requires +4 KJ of energy when dissolved in water. So, CaCl2 shows exothermic reaction and NaCl shows endothermic reaction.
Solublity of both salts increases as the temperature increases because on heating particles are in motion and they releases energy and this energy is used for the hydration so the hydration energy increases from the lattice energy and it favours more solublity of salt.
The ion dipole interaction with water to overcome strong columbic attraction and it produces aqueous solution. Ions in aqueous solutions bound to water molecules through ion-dipole interactions. The number of water molecules in the primary hydration shell, enters the ion with the radius and charge of the ion. As the radius and charge is more on Ca2+ , so the ion-dipole interaction is more for CaCl2.