unbranched Alkane \( (x) \) its molar mass \( =114 \mathrm{~g} / \mathrm{mol} \) this alkane contains (Quiz 13 L3 Ch5) [C=12, \( \mathrm{H}=1] \) a) 6 methylene groups, 2 methyl groups b) 2 methylene groups, 6 methyl groups c) 4 methylene groups, 4 methyl groups d) 2 methylene groups, 2 methyl groups

To identify the structure of the unbranched alkane with a molar mass of 114 g/mol, let’s first calculate the molecular formula. The general formula for an alkane is \( C_nH_{2n+2} \). Using the molar mass, we can find \( n \). Calculating, we find \( n = 8 \), which gives us the formula \( C_8H_{18} \) (octane). This alkane has 4 methylene groups (each contributing a carbon atom and two hydrogen atoms) and 4 methyl groups at the ends. So the correct answer is: **c) 4 methylene groups, 4 methyl groups.** For further insight, did you know that octane is not just a fuel component but also a key factor in determining gasoline's performance? The octane rating is a measure of a fuel's resistance to knocking, which is crucial for efficient engine function. Moreover, if you ever find yourself confused about differentiation of hydrocarbons, try drawing out the structural formulae! Visualizing the arrangement can often clarify how many methyl or methylene groups sit within your molecules, making it easier to avoid common mix-ups.