Answer:
49.8 g C₆H₅Br
Step-by-step explanation:
The theoretical yield is the maximum calculated amount of product that can be made from a reaction. To find the theoretical yield, you need to (1) determine the chemical reaction which is taking place, then (2) calculate the molar masses of the relevant reactants and product, then (3) convert grams of each reactant to grams of bromobenzene (using molar masses and mole-to-mole ratio from reaction coefficients), and then (4) determine the limiting reagent and the theoretical yield.
(Step 1)
Bromine = Br₂
Benzene = C₆H₆
Bromobenzene = C₆H₅Br
The balanced equation:
Br₂ + 2 C₆H₆ ----> 2 C₆H₅Br + H₂
(Step 2)
Molar Mass (Br₂): 2(79.904 g/mol)
Molar Mass (Br₂): 159.808 g/mol
Molar Mass (C₆H₆): 6(12.011 g/mol) + 6(1.008 g/mol)
Molar Mass (C₆H₆): 78.114 g/mol
Molar Mass (C₆H₅Br): 6(12.011 g/mol) + 5(1.008 g/mol) + 79.904 g/mol
Molar Mass (C₆H₅Br): 157.01 g/mol
(Step 3)
52.3 g Br₂ 1 mole 2 moles C₆H₅Br 157.01 g
----------------- x ------------------ x ------------------------- x --------------- =
159.808 g 1 mole Br₂ 1 mole
= 103 g C₆H₅Br
24.8 g C₆H₆ 1 mole 2 moles C₆H₅Br 157.01 g
------------------- x --------------- x -------------------------- x --------------- =
78.114 g 2 moles C₆H₆ 1 mole
= 49.8 g C₆H₅Br
(Step 4)
Because C₆H₆ produces a smaller amount of product than Br₂, it must be the limiting reagent. This means that it will run out before all of the Br₂ is used up. Therefore, the actual theoretical yield of C₆H₅Br is 49.8 grams.