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each question contain STATEMENT-1(Assert...

each question contain STATEMENT-1(Assertion ) and STATEMENT - 2 (reason). examine the statement carefully and work the correct answer according to the instructions given below :
STATEMENT-1: The micelle formed by sodium sterate in water has- `COO^(-)` groups at the surface.
STATEMENT-2: Surface tension of water is reduced by the addition of sterate.

A

if both the statement are TRUE and STATEMENT -2 is the correct explanation of STATEMENT - 1

B

If both the statement are STATEMENT -2 is NOT the correct explanation of STATEMENT -1

C

If STATEMENT -1 is TRUE and STATEMENT is FALSE

D

If STATEMENT -1 is FALSE and STATEMENT -2 is TRUE

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both statements carefully. ### Step 1: Analyze Statement 1 **Statement 1:** The micelle formed by sodium stearate in water has `COO^(-)` groups at the surface. - Sodium stearate (a soap) dissociates in water into sodium ions (Na⁺) and stearate ions (RCOO⁻). - The stearate ion has a long hydrophobic hydrocarbon chain and a hydrophilic carboxylate group (`COO^(-)`). - When micelles form, the hydrophobic parts (the hydrocarbon chains) aggregate in the center, while the hydrophilic parts (the `COO^(-)` groups) orient towards the water, forming the surface of the micelle. **Conclusion for Statement 1:** This statement is true because the micelle indeed has `COO^(-)` groups at its surface. ### Step 2: Analyze Statement 2 **Statement 2:** Surface tension of water is reduced by the addition of stearate. - When sodium stearate is added to water, the stearate ions replace some of the water molecules at the surface. - This replacement reduces the cohesive forces between water molecules, leading to a decrease in surface tension. **Conclusion for Statement 2:** This statement is also true because the addition of stearate does reduce the surface tension of water. ### Step 3: Determine the Relationship Between the Statements - Both statements are true. - However, Statement 2 does not directly explain Statement 1. While both are true, the reason provided in Statement 2 does not clarify why the `COO^(-)` groups are at the surface of the micelle. ### Final Answer Both statements are true, but Statement 2 is not the correct explanation for Statement 1. Therefore, the correct answer is: **Option 2:** Both statements are true, but Statement 2 is not the correct explanation for Statement 1. ---
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