Question

a polymeric organic compound has formula (C6H3) (C8H8)nBr3. if it contains 7.68% bromine, then the value of n will be (approximate)​

Answer 1

Given:

A polymeric organic compound has formula (C6H3) (C8H8)nBr3.

To Find:

If it contains 7.68% bromine, then the value of n will be (approximate)​ ?

Solution:

since, we know that-

formula of the compound = $(C_{6}H_{3})(C_{8}H_{8})_{n}Br_{3}$

mass % of the Br, $W_{Br}$% = 7.68%

mass of Br in the compound = 240u

Now, let

M = Molecular mass of the compound = 75+104 n +240 = 315+104n

therefore,

7.68% of M =240 u

$\dfrac{7.68}{100}\times M=240 u\\\\M=\dfrac{240\times100}{7.68}\\\\315+104n=3125\\\\104n=3125-315\\\\104n=2810\\\\n=27.01923$

⇒ n ≈ 27

Hence, the value of n is 27.