Step 1: Understanding the Concept:
The image displays a skeletal chemical structure. In such structures, the lines represent chemical bonds, and the vertices or endpoints of lines (that are not explicitly labelled with other atoms) represent carbon atoms. Hydrogen atoms bonded to carbon are implied to fulfill carbon's valency of four. Step 2: Key Formula or Approach:
Identify the molecular formula from the given skeletal structure, then calculate its molar mass using the standard atomic weights of the constituent elements. Step 3: Detailed Explanation:
The structure shows a two-carbon chain with an \(\text{OH}\) group attached.
- The unlabelled end of the line represents a methyl group (\(\text{CH}_3\)).
- The vertex represents a methylene group (\(\text{CH}_2\)).
- The line then connects to a hydroxyl group (\(\text{OH}\)).
So, the chemical formula of the compound is \(\text{CH}_3-\text{CH}_2-\text{OH}\), which is ethanol.
The molecular formula of ethanol is \(\text{C}_2\text{H}_6\text{O}\).
Now, calculate its molar mass using standard atomic weights:
\[ \text{C} = 12\text{ g/mol}, \text{H} = 1\text{ g/mol}, \text{O} = 16\text{ g/mol} \]
\[ \text{Molar mass} = (2 \times 12) + (6 \times 1) + (1 \times 16) \]
\[ \text{Molar mass} = 24 + 6 + 16 = 46\text{ g mol}^{-1} \]
Step 4: Final Answer:
The molar mass is \(46\text{ g mol}^{-1}\), matching option (B).
