Answer:
0.736
Step-by-step explanation:
*I am not sure what you mean by "carbon tetrahedral". I'm assuming you are just referring to individual carbon.*
To find the mole percent, you need to (1) convert grams benzene and grams carbon to moles (via their molar masses) and then (2) calculate the mole fraction (via the mole fraction formula).
(Step 1)
Benzene = C₆H₆
Molar Mass (C₆H₆) = 6(12.01 g/mol) + 6(1.008 g/mol)
Molar Mass (C₆H₆) = 78.108 g/mol
70 g C₆H₆ 1 mole
--------------- x ------------------ = 0.896 mole C₆H₆
78.108 g
Molar Mass (C) = 12.01 g/mol
30 g C 1 mole
------------ x ----------------- = 2.50 mole C
12.01 g
(Step 2)
moles solute
Mole Fraction = ----------------------------------------------
moles solute + moles solvent
2.50 mole C
Mole Fraction = ------------------------------------------------- = 0.736
(0.896 mole C₆H₆ + 2.50 mole C)