What happens when A mixture of ethene and steam is passed over phosphoric acid on silica at `300^@C` and 70 atm.

Explanation

To solve the question of what happens when a mixture of ethene and steam is passed over phosphoric acid on silica at 300°C and 70 atm, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this reaction are ethene (C₂H₄) and steam (H₂O).

2. **Understand the Conditions**: The reaction occurs in the presence of phosphoric acid (H₃PO₄) as a catalyst, at a temperature of 300°C and a pressure of 70 atm.

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