Answer to Question #165378 in Organic Chemistry for Beauty

Question

An organic compound A made up to 87.8% Carbon and 12.2% Hydrogen; reacts with cold dilute KMnO₄ to yield D (C₆H₁₂O₂). A takes up only one mole of hydrogen gas to form B when hydrogenated. A also decolourises aqueous Bromine to form C. (RAM of C = 12, H = 1.00, O = 16)

• Determine the molecular formula of A. Hence give the structures of A, B, C & D
• Compound C and D exist in several configurations. Draw the structures of any two configurations of either C or D.

Answer 1

Moles of carbon = 87.8 / 12 = 7.32

Moles of Hydrogen = 12.2 / 1 = 12.2

Both are devided by 3.5 then

Moles of carbon = 7.32 / 3.5 = 2.02

Moles of hydrogen = 12.2 / 3.5 = 3.5

Moar ratio of carbon and hydrogen = 4 : 7

Emperical formula = C₄ H₇ .