Final Answer:
Among CH₃CH₂SH and CH₃CH₂OH, CH₃CH₂SH is the stronger acid.
Step-by-step explanation:
In organic chemistry, the strength of an acid is often determined by its ability to donate a proton (H⁺ ion). The key factor influencing acidity is the stability of the conjugate base formed after the acid loses a proton. In this case, we can compare the stability of the conjugate bases of CH₃CH₂SH and CH₃CH₂OH.
Firstly, let's consider the conjugate base of CH₃CH₂SH, which is derived by removing a proton (H⁺) from the sulfur atom. The resulting ion is CH₃CH₂S⁻. Sulfur is more electronegative than oxygen, and the larger size of sulfur allows for a more stable negative charge. Therefore, CH₃CH₂S⁻ is more stable than the conjugate base of CH₃CH₂OH.
Secondly, the conjugate base of CH₃CH₂OH is CH₃CH₂O⁻, which is less stable compared to CH₃CH₂S⁻ due to the higher electronegativity of oxygen. The greater electronegativity of oxygen results in a more localized negative charge, making the conjugate base less stable.
In summary, CH₃CH₂SH is the stronger acid because its conjugate base, CH₃CH₂S⁻, is more stable than the conjugate base of CH₃CH₂OH. This stability is attributed to the electronegativity and size of the atom carrying the negative charge.