The amount of moisture that leather adsorbs or loses is determined by temperature, relative humidity, degree of porosity, and the size of the pores. Moisture has great practical significance because its amount affects the durability of leather, and in articles such as shoes, gloves, and other garments, the comfort of the wearer. High moisture content accelerates deterioration and promotes mildew action. On the other hand, a minimum amount of moisture is required to keep leather properly lubricated and thus prevent cracking.
The study indicates that adsorption of moisture by leather is a multi-molecular process and is accompanied by low enthalpies of adsorption. Further 75-percent relative humidity the adsorption is a function of surface area alone. Untanned hide and chrome-tanned leathers have the largest surface areas. The leathers tanned with the vegetable tanning materials have smaller surface areas since they are composed of less hide substance and the capillaries are reduced to smaller diameters, in some cases probably completely filled by tanning materials. This process of tanning occurs due to mutual coagulation of positively charged hide with negatively charged tanning material. The result of the study indicated that untanned hide and chrome-tanned leather adsorb the most water vapour.
Assertion: Vegetable tanned leather cannot adsorb a large amount of moisture.
Reason: Porous materials have higher surface area.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.

Answer

To solve the question regarding the assertion and reason related to the moisture adsorption capacity of vegetable-tanned leather, we will break down the information provided in the passage step by step.

### Step 1: Understanding the Assertion
The assertion states that "vegetable-tanned leather cannot adsorb a large amount of moisture." This is based on the information that vegetable-tanned leather has a smaller surface area compared to untanned hide and chrome-tanned leather.

**Hint:** Consider the relationship between surface area and moisture adsorption.

### Step 2: Analyzing the Reason
The reason provided is that "porous materials have higher surface area." This is generally true, as porous materials contain numerous pores that increase their overall surface area, allowing for greater adsorption capabilities.

**Hint:** Think about how the presence of pores contributes to surface area.

### Step 3: Relating Assertion to Reason
While both statements are true, we need to determine if the reason correctly explains the assertion. The assertion is specifically about vegetable-tanned leather's ability to adsorb moisture, while the reason discusses porous materials in general.

**Hint:** Reflect on whether the reason directly addresses why vegetable-tanned leather has lower moisture adsorption.

### Step 4: Conclusion
Since the assertion is true (vegetable-tanned leather does have a lower moisture adsorption capacity due to its smaller surface area), and the reason is also true (porous materials generally have higher surface area), but the reason does not specifically explain the assertion about vegetable-tanned leather, we conclude that:

- Both the assertion and reason are correct, but the reason does not correctly explain the assertion.

**Final Answer:** The correct option is that both the assertion and reason are correct, but the reason does not correctly explain the assertion.