Final answer:
The fraction of the total pressure exerted by ethane is 0.5
Step-by-step explanation:
The fraction of the total pressure exerted by ethane can be determined by using Dalton's law of partial pressures. According to Dalton's law, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each gas.
In this case, since equal volumes of methane and ethane are mixed, they will exert the same partial pressure. Therefore, the fraction of the total pressure exerted by ethane is 1/2 or 0.5.