What is the shape of the nitrosyl hydride molecule
Nitrosyl hydride, also known as nitroxyl or HNO, has a bent molecular geometry. In this molecule, the nitrogen atom is bonded to an oxygen atom and a hydrogen atom. The NO bond is a polar covalent bond, and there's a significant amount of charge separation between the nitrogen and the oxygen, giving the molecule a dipole moment.
If you consider the valence shell electron pair repulsion (VSEPR) theory, the molecular shape can be explained as follows: The nitrogen atom has a lone pair of electrons in addition to the two bonds with oxygen and hydrogen. This lone pair and the two bonded pairs create a trigonal planar arrangement with electron pairs around the nitrogen, but since the lone pair is not seen in the molecular geometry, the shape is bent (similar to water, H2O).
The HNO angle is generally not exactly 120°, which would be the angle if the molecule were perfectly trigonal planar surrounding the nitrogen. Instead, the lone pair-bond pair repulsion causes the molecule to have a smaller H-N-O bond angle, typically found to be around 110° in experimental studies.