Question

A compound of only carbon and bromine consists of 10.15% carbon and has a molar mass of 707.70 g/mol. Determine the molecular formula of this compound.

Please answer with correct number of sig figs, scientific notation, and btw this question has two parts.

Answer 1

Assuming that you have 100g of the compound; Mass of Carbon=10.15 and mass of Br=(100-10.150) =89.85

C Br

Mass 10.15 89.85

RAM 16 35

Moles $\dfrac{10.15}{12}$ $\dfrac{89.85}{35}$

0.84583 2.56714

Mole ratios $\dfrac{0.84583}{0.84583}$ $\dfrac{2.56714}{0.84583}$

1 : 3

Empirical formula = CBr₃

(CBr₃)_n = 707.7

(12+105)n =707.7

$\dfrac{117n}{117}=\dfrac{707.7}{117}$

n=6.05

MF=(CBr₃)₆ = C₆Br₁₂