Answer:
2.) C₆H₆O₂
Step-by-step explanation:
(Step 1)
To find the molecular formula of hydroquinone, you need to first determine the molar mass of the empirical formula. The molar mass is a sum of the individual atomic weights of each element multiplied by their quantities (denoted by the subscripts).
Atomic Weights:
Carbon (C): 12.011 g/mol
Hydrogen (H): 1.008 g/mol
Oxygen (O): 15.998 g/mol
Molar Mass (C₃H₃O): 3(12.011 g/mol) + 3(1.008 g/mol) + 15.998 g/mol
Molar Mass (C₃H₃O): 55.055 g/mol
(Step 2)
As you can see, the molar mass of the empirical formula is not the same as the molar mass of the molecular formula. Rather, the empirical molar mass is approximately half of the molecular molar mass. Therefore, to make these masses equal, we need to double the empirical formula. This can be done by multiplying all of the subscripts by 2.
55.055 g/mol x 2 = 110.11 g/mol
110.11 g/mol = 110.108 g/mol
C₃ x 2 = C₆
H₃ x 2 = H₆
O x 2 = O₂
Therefore, the correct molecular formula of hydroquinone is C₆H₆O₂.