Why did acetonitrile has more polar than acetaldehyde

The cyano group in acetonitrile consists of a C and N atom, which are bonded by an SP hybrid triple bond. The greater the contribution of the "s" component in the hybrid orbital, the higher the electronegativity. As a result, the cyano group attracts more electrons compared to the hydroxymethyl group in the molecule, leading to a larger dipole moment. In contrast, ethanol molecules in solution exhibit a sawtooth shape and can form intermolecular hydrogen bonds. However, acetonitrile has a linear structure, resulting in a more concentrated dipole moment. Therefore, acetonitrile exhibits greater polarity due to these factors. To summarize, the higher electronegativity and linear structure of acetonitrile contribute to its larger dipole moment and overall greater polarity compared to ethanol.