Find the order of the reaction in which a gas is formed at the surface of tungsten due to adsorption.

Explanation

To find the order of the reaction in which a gas is formed at the surface of tungsten due to adsorption, we can follow these steps:

### Step 1: Understand the Process of Adsorption
Adsorption is the process where molecules from a gas or liquid adhere to a solid surface. In this case, we are considering the adsorption of a gas on the surface of tungsten.

**Hint:** Remember that adsorption involves the interaction of gas molecules with a solid surface.

### Step 2: Identify the Reaction Order
In chemical kinetics, the order of a reaction is determined by how the rate of the reaction depends on the concentration of the reactants. For reactions involving adsorption on solid surfaces, it has been observed that the rate of formation of gas does not depend on the concentration of the gas once the surface is saturated.

**Hint:** Consider how the concentration of the adsorbed species affects the rate of reaction.

### Step 3: Determine the Order of the Reaction
For reactions involving adsorption on surfaces like tungsten, palladium, or platinum, it is established that these reactions typically follow zero-order kinetics. This means that the rate of reaction is constant and does not change with the concentration of the reactants.

**Hint:** Recall that zero-order reactions have a rate that is independent of the concentration of the reactants.

### Conclusion
Thus, the order of the reaction in which a gas is formed at the surface of tungsten due to adsorption is **zero order**.

**Final Answer:** 0