Question

If the weight of a sample of cotton decreases from 107.5 to 100 grams when heated at 105 °C for 2 hours. The Moisture Content and Regain is

• A. 7.0 and 7.5
• B. 8.0 and 8.5
• C. 9.0 and 9.5
• D. 8.5 and 9.0

Hint:

Moisture Content is based on the total weight, while Moisture Regain is based on the dry weight. Regain will always be a higher percentage than content for the same sample.

Answer 1

The Correct Option is A

Step 1: Understanding Moisture Content and Regain: Moisture Content (MC): The amount of moisture in a material, expressed as a percentage of the total (wet) weight. Moisture Regain (MR): The amount of moisture in a material, expressed as a percentage of the dry weight.
Step 2: Calculating Weight Loss (Moisture Loss): \[ \text{Weight Loss} = \text{Initial Weight} - \text{Dry Weight} = 107.5 \text{ g} - 100 \text{ g} = 7.5 \text{ g} \]
Step 3: Calculating Moisture Content: \[ \text{Moisture Content (%)} = \frac{\text{Weight Loss}}{\text{Initial Weight}} \times 100% \] \[ \text{Moisture Content (%)} = \frac{7.5 \text{ g}}{107.5 \text{ g}} \times 100% = 6.9767 % \approx 7.0% \]
Step 4: Calculating Moisture Regain: \[ \text{Moisture Regain (%)} = \frac{\text{Weight Loss}}{\text{Dry Weight}} \times 100% \] \[ \text{Moisture Regain (%)} = \frac{7.5 \text{ g}}{100 \text{ g}} \times 100% = 7.5% \]