Question

Identify whether each process is spontaneous or non-spontaneous.
1. Silverwares tarnish when exposed to air.
2. Table salt dissociates into sodium and chlorine ions in water.
3. Water molecules form from hydrogen and oxygen.​

Answer 1

Answer: 1. Spontaneous

2. Spontaneous

3. Non-spontaneous

Explanation:

Answer 2

The following processes can be classified into spontaneous and non-spontaneous as-

• Tarnishing of silverware is a non-spontaneous reaction as it takes time for silver to react with sulfur-containing gases to form silver sulfide which causes the blackness of the surface of the metal.

• The dissociation of salt in water, into sodium and chlorine ions, is a spontaneous reaction despite being endothermic because the hydration energy of the salt molecules is greater than their lattice energy. It dissociates really quick until it reaches the saturation point

• The formation of water molecules from hydrogen and oxygen does not happen at normal room temperature without providing activation energy. So, it classifies as a non-spontaneous reaction.