Question

If the reaction shown was carried out by allowing 8.195 mL of cyclohexane (M.W. 82.15, d 0.811 g/mL) to react with excess bromine, what is the theoretical yield (in grams) of the 1,2-dibromocyclohexane (M.W. 241.96)?

Answer 1

Ans :- Theoretical yield (in grams) of the 1,2-dibromocyclohexane = 19.58 g

Explanation :-

Mass of Cyclohexane (C₆H₁₂) = Density x Volume

= 0.811 g/mL x 8.195 mL

= 6.646 g

Number of moles of C₆H₁₂ = Mass/M.W

= 6.646 g / 82.15 g/mol

= 0.0809 mol

Balanced chemical equation is :

C₆H₁₂ + 2 Br₂ --------------> C₆H₁₀Br₂ + 2 HBr

In the balanced chemical equation, it is cleared that,

1 mol of C₆H₁₂ (cyclohexane) gives = 1 mol of C₆H₁₀Br₂ ( 1,2-dibromocyclohexane)

So,

0.0809 mol of C₆H₁₂ (cyclohexane) gives = 0.0809 mol of C₆H₁₀Br₂ ( 1,2-dibromocyclohexane)

So,

Mass of C₆H₁₀Br₂ = Moles x M.W

= 0.0809 mol x 241.96 g/mol

= 19.58 g

Hence, Theoretical yield (in grams) of the 1,2-dibromocyclohexane = 19.58 g