Imbibition: Characteristics, Factors, Conditions & Significance

Ans. Imbibition is the absorption of water by some solid colloidal particles of an adsorbent making it tremendously expand in volume without forming a solution. These solid colloidal particles or adsorbents increase their volume after retaining a certain amount of liquid which is sometimes referred to as imbibants and the liquid being adsorbed is known as imbibate.

Example- swelling of seeds when soaked in water.

Wooden doors become heavier in the rainy season.

Ans. Diffusion - It is the movement of solid, liquid, or gaseous ions from high concentration to lower concentration.

It is irreversible in nature and can only occur on living surfaces.

On contrary to this

Imbibition is the movement of liquid from higher to lower water potential.

It is reversible in nature and occurs in both living and dead surfaces.

Ans. The basic difference between imbibition and osmosis is that imbibition is the adsorption of water by solid surfaces and osmosis usually refers to the general movement of water across high to low concentrations.

Ans. Imbibition plays a crucial role in the life of plants because of the following points:

•  It is because of imbibition that the water reaches the ovule and then further ripens it into seeds.
• Due to an increase in imbibition pressure inside the seeds it eventually breaks down and the seedling manages to reach above the soil.
• It provides necessary hydration to seeds and keeps them moist.
• It is considered to be the first step in the germination of seeds and water adsorption.
• It facilitates water absorption in the roots of plants.

Ans. Water potential is the difference in the potential energy of water molecules to move from one area to another due to differences in their pressure. Water potential on the other hand is the difference between the potential energies of two liquids. For example, when a dry seed comes in contact with water the water rapidly diffuses into seed, in other words, the liquid diffuses from higher water potential to lower water potential.

Ans. Factors affecting Imbibition are as follows

Temperature - The rate of imbibition increases with an increase in temperature.

Pressure - The rate of imbibition increases with an increase in pressure.

PH value of the medium.

Hydrophilic Capacity of the imbibate to attract a water molecule.

The affinity between the imbibant and imbibate.

Force of attraction between imbibant and imbibate.

Ans. Water potential - The water potential gradient between the imbibant and imbibate is established because the imbibants have a negative value for water potential on the other hand the water potential of pure water is considered to be zero. Due to this when a dry seed comes in contact with water the water rapidly diffuses into the seed, in other words, the liquid diffuses from higher water potential to lower water potential.

• The heat of Wetting- Energy is released in the form of heat during the process of imbibition.
• Increase in Pressure and volume- As the liquid diffuses inside the imbibant it swells up or it increases its volume which in turn increases the overall pressure in the imbibant. This pressure is known as imbibition Pressure, it is very high in magnitude. For example, it requires atleast 1000atm pressure to break down the seed and help it reach above the ground. This pressure is being generated through imbibition.

Ans. Following are the three necessary conditions to achieve imbibition

1. i) A water potential gradient between imbibate and imbibant, the more the difference in potential of two liquids more rapidly the water molecules will move.
2. ii) Moderate to high temperature as an increase in temperature or warm climate accelerates the rate of imbibition.

iii) Force of attraction between imbibate and imbibant, the stronger the force of attraction between water and solid particles, the higher will be the rate of adsorption.