Question

1- We looked at NaCl before it dissolved and after it dissolved. Now,1- draw a picture of NaCl while it dissolves. Make sure to include both NaCl and H2O.

2- describe the sequence of events that happens when solid NaCl dissolves in water.

3- How is energy transferred between the system and the surroundings during this process?

Answer 1

Ans 1

This figure shows how NaCl dissolves in water. Here in the left side salt crystal is shown which is dissolving and in the right side dissolved particles are shown.

Ans 2:

When NaCl crystals are dipped in water, cleavage of ionic bond takes place which is compensated by the surrounding water molecules. After the cleavage Na⁺ and Cl^- ions are formed. Since we know that water molecules are polar in nature in which oxygen is more electronegative in nature than hydrogen. Hence water molecules forms a layer around the ions and energy is released known as hydration enthalpy which compensated the lattice energy of the NaCl molecules. In this way NaCl is dissolved in water.

Ans 3:

During the cleavage of ionic bond energy is transferred from surrounding to system as energy is needed for the cleavage of ionic bond. After this water molecules form layers around the ions in which energy is released. This energy is transferred from system to the surrounding.