As a result of the addition of hydrogen to benzene with a mass of 7.8 g, cyclohexane with a mass of (g) is formed.

1. The addition of hydrogen to benzene proceeds according to the reaction equation:
C6H6 + 3H2 → C6H12;
2. Determine the chemical amounts of benzene and the resulting cyclohexane:
n (C6H6) = m (C6H6): M (C6H6);
M (C6H6) = 6 * 12 + 6 = 78 g / mol;
n (C6H6) = 7.8: 78 = 0.1 mol;
n (C6H12) = n (C6H6) = 0.1 mol;
3. Calculate the mass of cyclohexane:
m (C6H12) = n (C6H12) * M (C6H12);
M (C6H12) = 6 * 12 + 12 = 84 g / mol;
m (C6H12) = 0.1 * 84 = 8.4 g.
Answer: 8.4 g.