Here's how to calculate the percent composition of hydrogen in benzene (C₆H₆):

1. Find the molar mass of benzene:

* Carbon (C): 12.01 g/mol * 6 = 72.06 g/mol

* Hydrogen (H): 1.01 g/mol * 6 = 6.06 g/mol

* Total molar mass of benzene: 72.06 g/mol + 6.06 g/mol = 78.12 g/mol

2. Calculate the mass percentage of hydrogen:

* (Mass of hydrogen / Molar mass of benzene) * 100%

* (6.06 g/mol / 78.12 g/mol) * 100% = 7.74%

Therefore, the percent composition of hydrogen in benzene is 7.74%.