Name the catalyst used in the Haber process.

The catalyst used in the Haber process is iron. The Haber process is a method of synthesizing ammonia from nitrogen and hydrogen gases, and iron serves as an effective catalyst in this reaction. The primary role of the catalyst is to increase the rate of the reaction without being consumed in the process.

In the Haber process, the reaction occurs at high temperatures and pressures, typically around 450 degrees Celsius and pressures of 200 atmospheres. Iron's catalytic properties facilitate the breaking of the triple bond in nitrogen molecules, making it easier for nitrogen and hydrogen to combine to form ammonia.

While other metals are indeed used as catalysts in various chemical processes, iron remains the primary choice in the Haber process due to its availability, cost-effectiveness, and efficiency in promoting the necessary reactions to produce ammonia at industrial scales.