See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

Step 1: Identify the molecule. The structure shown is morpholine, a six-membered saturated heterocyclic ring containing one oxygen atom and one nitrogen atom bearing one hydrogen (N-H), with four CH2 groups. Step 2: Count lone pairs on each heteroatom. - Oxygen atom in the ring: Oxygen has 6 valence electrons. It forms 2 single bonds (to two carbon atoms), using 2 electrons in bonding. Remaining electrons = 6 - 2 = 4 electrons = 2 lone pairs. - Nitrogen atom (N-H) in the ring: Nitrogen has 5 valence electrons. It forms 3 bonds (two C-N bonds and one N-H bond), using 3 electrons in bonding. Remaining electrons = 5 - 3 = 2 electrons = 1 lone pair. Step 3: Sum the lone pairs. - Oxygen: 2 lone pairs - Nitrogen: 1 lone pair - Total = 2 + 1 = 3 lone pairs Step 4: Evaluate the options. - (a) 2: Incorrect, this would only count the lone pairs on oxygen. - (b) 3: Correct, 2 (on O) + 1 (on N) = 3 lone pairs total. - (c) 4: Incorrect, this would overcounts the lone pairs. - (d) 5: Incorrect, significantly overcounts. Note: Carbon and hydrogen atoms in this molecule do not contribute lone pairs under standard Lewis structure counting. Therefore, the correct answer is B.