Write structural formula for the following compounds
(i) Cyclohexa-1, 4-diene
(ii) Ethynyl cyclohexane.

Write all the possible isomers of molecular formula C₄H₁₀O and identify the isomerisms found in them.

0.16 g of an organic compound was heated in a carius tube and H₂SO₄ acid formed was precipitated with BaCl₂. The mass of BaSO₄ was 0.35g. Find the percentage of sulphur [30.04]

0.40 g of an iodo-substituted organic compound gave 0.235 g of AgI by carius method. Calculate the percentage of iodine in the compound. (Ag = 108, I = 127)

0.33 g of an organic compound containing phosphorous gave 0.397 g of Mg₂P₂O₇ by the analysis. Calculate the percentage of P in the compound.