Problem 77 - Chemistry: The Central Science

Question

Draw the condensed structural formulas for two different molecules with the formula \(\mathrm{C}_{3} \mathrm{H}_{4} \mathrm{O}\).

Step-by-Step Solution

Answer

Two condensed structural formulas for the molecular formula \(\mathrm{C}_{3} \mathrm{H}_{4} \mathrm{O}\) are: 1. H-C≡C-CH₂OH 2. \(\begin{array}{c} \ce{H2C-CH2} \\ || \\ \ce{O} \end{array}\)

Step 1: Identify the index of hydrogen deficiency (IHD)

To determine the IHD, we'll use the formula: IHD = (2*number of carbons + 2 - number of hydrogens) / 2. In this case, we have: IHD = (2 * 3 + 2 - 4) / 2 = (6 + 2 - 4) / 2 = 4 / 2 = 2 An IHD of 2 means that there are two double bonds or one ring and one double bond or one triple bond in the molecule.

Step 2: Draw the first condensed structural formula

One possible arrangement would be a molecule with one triple bond between two carbons and the third carbon bonded to an oxygen atom. The first condensed structural formula is: H-C≡C-CH₂OH This structure satisfies the octet rule for all atoms and corresponds to the molecular formula \(\mathrm{C}_{3} \mathrm{H}_{4} \mathrm{O}\).

Step 3: Draw the second condensed structural formula

Another possible arrangement would be a molecule with a ring structure containing one double bond, and an oxygen atom forming the ring. The second condensed structural formula is: \(\begin{array}{c} \ce{H2C-CH2} \\ || \\ \ce{O} \end{array}\) This structure also satisfies the octet rule for all atoms and corresponds to the molecular formula \(\mathrm{C}_{3} \mathrm{H}_{4} \mathrm{O}\).