Question

Based on observations during the lab, which molecules below have a three-dimensional structure? (Select all that apply.)

a) Ethanol (C2H5OH)
b) Carbon dioxide (CO2)
c) Water (H2O)
d) Methane (CH4)

Answer 1

Ethanol (C2H5OH), Water (H2O), and Methane (CH4) have three-dimensional structures, while Carbon dioxide (CO2) has a linear structure and does not.

Step-by-step explanation:

Based on observations during a lab, to identify molecules with a three-dimensional structure, we should look for any molecules that do not have linear or planar configurations but rather adopt spatial arrangements. Ethanol (C2H5OH), Water (H2O), and Methane (CH4) all have three-dimensional structures.

1. Ethanol (C2H5OH) has a bent carbon chain and the hydroxyl group (-OH) adds to the three-dimensionality of the molecule.
2. Water (H2O) has a bent structure, known as a V-shaped molecule, where the hydrogen atoms are not aligned linearly but are angled due to electron pair repulsion.
3. Methane (CH4) has a tetrahedral structure, with carbon at the center and hydrogen atoms at the corners of a tetrahedron.

Carbon dioxide (CO2), which is not listed in the materials provided, has a linear structure and therefore is not a three-dimensional molecule.