Answer:
0.38
Step-by-step explanation:
Molar mass of thiophene= 84g/mol
Mass of thiophene = 37g
Number of moles= 37/84= 0.44 moles
Molar mass of heptane= 100 g/mol
Mass of heptane = 72g
Number of moles = 72/100= 0.72 moles
Total number of moles= 0.44 + 0.72= 1.16 moles
mole fraction of thiophene = 0.44/1.16= 0.38