Question

Dry wooden stakes driven in cracks of a rock and soaked will develop pressure that will split the rock. The phenomenon is
A) Osmotic pressure
B) Imbibition
C) Turgor pressure
D) Deplasmolysis

Answer 1

Wood or rocks when soaked in water absorbs water from the surrounding. This water will fill the intermolecular space and as a result can cause split. It is a natural phenomenon. This kind of phenomenon is also seen in seeds when soaked in water swell and split.

Complete answer:
The dry wood or rock when soaked in water swell up and at times split or develop cracks. This phenomenon can be explained by a special kind of diffusion of solvent particles. In this, the solvent particles move from its region of higher concentration (surroundings) to the region of lower concentration (inside dry wood or rock). It occupies the space between the molecules and exerts pressure on the surface. This pressure causes the split. The process involved here is imbibitions as it does not involve any membrane barrier and increases the volume.
Thus imbibitions can be defined as a special type of diffusion in which the water is absorbed by the solids as a result of which the volume increases.

Osmotic pressure- It is the pressure applied by the solvent to prevent it from passing.
Turgor pressure- is the pressure applied by the osmosis on the walls of the cells.
Deplasmolysis- It is the swelling or entry of water to a plasmolysed cell.

Thus the correct answer is (B). Imbibition causes cracks in rock and dry wood.

Note: Few examples of imbibitions are swelling of the seeds and bursting of seed coat during seed germination. The wooden doors become tight during the rainy season as they absorb moisture from the surrounding.