Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Which of the following molecules is chiral?
A
ethanol
B
2-butanol
C
propane
D
acetone
Verified step by step guidance
1
Understand the concept of chirality: A molecule is chiral if it has a non-superimposable mirror image, often due to the presence of an asymmetric carbon atom (a carbon atom bonded to four different groups).
Examine ethanol: Ethanol (C₂H₅OH) has the structure CH₃CH₂OH. The carbon atoms in ethanol are bonded to hydrogen and oxygen atoms, but neither carbon is bonded to four different groups, so ethanol is not chiral.
Examine propane: Propane (C₃H₈) has the structure CH₃CH₂CH₃. All carbon atoms in propane are bonded to hydrogen atoms and other carbon atoms, but none are bonded to four different groups, so propane is not chiral.
Examine acetone: Acetone (C₃H₆O) has the structure CH₃COCH₃. The central carbon atom is bonded to two methyl groups and an oxygen atom, but not four different groups, so acetone is not chiral.
Examine 2-butanol: 2-butanol (C₄H₁₀O) has the structure CH₃CH(OH)CH₂CH₃. The second carbon atom is bonded to a hydroxyl group (OH), a methyl group (CH₃), an ethyl group (CH₂CH₃), and a hydrogen atom, making it an asymmetric carbon and thus chiral.