Incorrect statement about zeolites is

Options

A. Zeolites are shape selective catalysts
B. They have honeycomb like structure
C. The are 3 -D micro porous silicates containing AI-O-Si frame work
D. ZSM -5 ius used as catalyst for cracking and isomerisation of hydrocarbons

Answer

To determine the incorrect statement about zeolites, let's analyze the provided information step by step.

### Step 1: Understand Zeolites
Zeolites are microporous aluminosilicate minerals that have a three-dimensional framework structure. They are composed of silicon (Si), aluminum (Al), and oxygen (O) atoms.

**Hint:** Remember that zeolites have a specific structure that includes silicon and aluminum.

### Step 2: Structure of Zeolites
The structure of zeolites consists of a 3D network where silicon atoms can be partially replaced by aluminum atoms. This substitution creates a negative charge that is balanced by cations present in the structure.

**Hint:** Focus on how silicon and aluminum interact in the zeolite structure.

### Step 3: Catalytic Properties
Zeolites are known for their catalytic properties, particularly as shape-selective catalysts. This means they can selectively catalyze reactions based on the size and shape of the reactants and products.

**Hint:** Think about what "shape-selective" means in the context of catalysis.

### Step 4: ZSM-5 as a Catalyst
ZSM-5 is a specific type of zeolite that is widely used in the petrochemical industry. It is known for its applications in cracking and isomerization of hydrocarbons.

**Hint:** Recall the specific applications of ZSM-5 in catalysis.

### Step 5: Identify the Incorrect Statement
From the information provided, the statement that ZSM-5 is used as a catalyst for cracking but not for isomerization is incorrect. In fact, ZSM-5 is indeed used for both cracking and isomerization of hydrocarbons.

**Hint:** Check the applications of ZSM-5 carefully to spot any inaccuracies.

### Conclusion
The incorrect statement about zeolites is that ZSM-5 is not used for isomerization of hydrocarbons. In reality, ZSM-5 is used for both cracking and isomerization.

### Final Answer
The incorrect statement about zeolites is that ZSM-5 is not used for isomerization of hydrocarbons.