why would h2s have a smaller bond angle (93.38) than scl2 (97.90)?
H2s are two H atoms attached as in H-H. If that is what you mean, it has no bond angle (actually, it has one but it is 180 degrees as in a linear angle.)
it is due to the loan pairs in chlorine atoms,they repell fom each other so that bond angle increaces
To understand why H2S (hydrogen sulfide) has a smaller bond angle than SCl2 (sulfur dichloride), we need to consider the molecular structures and the properties of the atoms involved.
1. Molecular Structures:
- H2S: Hydrogen sulfide is a bent or V-shaped molecule. It consists of two hydrogen atoms (H) bonded to a central sulfur atom (S), creating a bent structure.
- SCl2: Sulfur dichloride is a linear molecule. It consists of a central sulfur atom bonded to two chlorine atoms (Cl), resulting in a linear structure.
2. Electronegativity Difference:
- Electronegativity is the measure of the attraction an atom has for electrons. It affects the distribution of electrons in a chemical bond.
- Chlorine (Cl) has a higher electronegativity value compared to sulfur (S). This means that in SCl2, chlorine atoms attract electrons more strongly than sulfur does.
- In H2S, sulfur and hydrogen have relatively similar electronegativity values.
The smaller bond angle in H2S compared to SCl2 can be explained by considering the repulsion between electron pairs around the central atom:
3. Electron Repulsion Theory:
- According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, electrons in a molecule arrange themselves in a way to minimize the repulsion between them.
- In H2S, there are two electron pairs (lone pair of electrons and a bonding pair) around the central sulfur atom. These electron pairs repel each other, causing the bonding pairs to move closer and compress the bond angle.
- In SCl2, there are only two bonding pairs (no lone pair). Since both chlorine atoms attract electrons strongly, the bonding pairs distribute themselves more towards the outer sides of the central sulfur atom. This leads to a larger bond angle compared to H2S.
In summary, the smaller bond angle in H2S (93.38°) compared to SCl2 (97.90°) can be attributed to the presence of a lone pair of electrons in H2S and the difference in electronegativity between the atoms in each molecule.