Give the correct order of initials T(true) or F(false) for following statements.
(a) Micelles formation takes place only above craft temperature
(b)ZSM-5 is a type of zeolites used as a catalyst in petrochemical industries.
(c)A micell is an aggregation of surfactants in in aqueous solution, often spherical
(d) Lyophilic sols are irreversible sols

Options

A. T F F T
B. T T F F
C. T T T F
D. F T T F

Answer

To determine the correct order of initials (T for true and F for false) for the given statements, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (a): Micelles formation takes place only above Kraft temperature.**
- **Analysis:** Micelles are formed when surfactants aggregate in solution, and this process requires energy. The Kraft temperature is the minimum temperature at which micelle formation occurs. Therefore, this statement is TRUE.
- **Initial:** T

2. **Statement (b): ZSM-5 is a type of zeolite used as a catalyst in petrochemical industries.**
- **Analysis:** ZSM-5 is indeed a well-known zeolite that is widely used as a catalyst in petrochemical processes, particularly for the isomerization of hydrocarbons. Thus, this statement is TRUE.
- **Initial:** T

3. **Statement (c): A micelle is an aggregation of surfactants in aqueous solution, often spherical.**
- **Analysis:** Micelles are formed by the aggregation of surfactant molecules in an aqueous solution, and they typically adopt a spherical shape to minimize energy. Therefore, this statement is TRUE.
- **Initial:** T

4. **Statement (d): Lyophilic sols are irreversible sols.**
- **Analysis:** Lyophilic sols exhibit strong interactions between the dispersed phase and the dispersion medium, which allows them to be reversible. They can be re-dispersed after coagulation. Hence, this statement is FALSE.
- **Initial:** F

### Final Order of Initials:
- (a) T
- (b) T
- (c) T
- (d) F

Thus, the correct order of initials is **T, T, T, F**.