For an equation N2(g)+3H2(g) double arrowed to give 2NH3(g) what is the catalyst?

To determine the catalyst in a chemical equation, you need to know some additional information. A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. In this case, the equation you provided represents the reaction between nitrogen gas (N2) and hydrogen gas (H2) to form ammonia gas (NH3).

The equation N2(g) + 3H2(g) ⇌ 2NH3(g) states that this reaction can proceed in both the forward and the reverse direction. The double arrow indicates that the reaction is reversible. However, it doesn't mention anything about the catalyst.

To identify the catalyst, you would need to refer to the specific condition or experimental setup for this reaction. Catalysts are often mentioned explicitly in the reaction conditions or experimental procedures. Without additional information, it is not possible to determine the catalyst in this particular equation.