Question

hydrogen-hydrogen single bond/s are broken and —— carbon-hydrogen single bond/s formed
options: 6;10, 2;10, 6;8, 2;8

Explanation:

To solve this problem, we analyze the reaction involving the breaking and forming of bonds:

Step 1: Analyze H - H bonds (Hydrogen - Hydrogen single bonds)

In the reaction, we start with \( \ce{2H_{2(g)}} \), which means there are 2 \( \ce{H - H} \) bonds (since each \( \ce{H_2} \) has 1 \( \ce{H - H} \) bond, and we have 2 moles of \( \ce{H_2} \)). These bonds are broken.

Step 2: Analyze C - C and C - H bonds (Carbon - Carbon and Carbon - Hydrogen bonds)

• The reactant has a carbon - carbon triple bond (\( \ce{C\equiv C} \)) and some C - H bonds. The product is a saturated (or more hydrogenated) compound.
• For the carbon - hydrogen bonds formed: Let's count the hydrogens. The product likely has 8 new C - H bonds (or considering the stoichiometry, the number of C - H bonds formed relates to the hydrogenation).
• For the carbon - carbon bonds: The triple bond (\( \ce{C\equiv C} \)) is converted (bonds broken: 2 \( \pi \)-bonds in the triple bond, but for single bonds broken/formed, the triple bond has 1 \( \sigma \) and 2 \( \pi \); when hydrogenated, we form single C - C bonds. However, focusing on the options, the first blank (H - H bonds broken) is 2, and the second (C - H bonds formed) is 8.

Answer:

2; 8 (matching the teal option: 2; 8)