1. The problem asks about the product of hydrogenation of benzene in the presence of a nickel catalyst at 180°C. 2. Hydrogenation is a chemical reaction where hydrogen (H2) is added to a compound, typically in the presence of a catalyst like nickel. 3. Benzene (C6H6) is an aromatic hydrocarbon with a stable ring structure. 4. When benzene undergoes hydrogenation, the double bonds in the ring are broken and hydrogen atoms are added, converting it into a saturated compound. 5. The product of benzene hydrogenation is cyclohexane (C6H12), a saturated cyclic hydrocarbon. 6. The reaction can be summarized as: $$\text{C}_6\text{H}_6 + 3\text{H}_2 \xrightarrow{\text{Ni catalyst, 180}^\circ\text{C}} \text{C}_6\text{H}_{12}$$ 7. This reaction is important in organic chemistry and industrial processes for producing cyclohexane, which is used in nylon production and other applications. Final answer: The hydrogenation of benzene in the presence of a nickel catalyst at 180°C produces cyclohexane (C6H12).