Sage-Tips

Why are the geometries of CH4 and SiH4 so similar?

Methane (CH4) and silane (SiH4) have same molecular shape. This is because atoms of carbon and silicon.

What shape does a methane molecule have?

tetrahedral
The molecular geometry of the methane molecule is tetrahedral (see Figure 7). The H-C-H bond angles are 109.5°, which is larger than the 90° that they would be if the molecule was planar.

What shape best describes a methane CH4 molecule?

The tetrahedral structure of methane (CH4) is explained in the VSEPR (valence-shell-electron-pair repulsion) theory of molecular shape by supposing that the four pairs of bonding electrons (represented by the gray clouds) adopt positions that minimize their mutual repulsion.

What is the orbital structure of CH4?

The bonds in a methane (CH4) molecule are formed by four separate but equivalent orbitals; a single 2s and three 2p orbitals of the carbon hybridize into four sp3 orbitals. In the ammonia molecule (NH3), 2s and 2p orbitals create four sp3hybrid orbitals, one of which is occupied by a lone pair of electrons.

Why are the geometries of H2S and H2O so similar?

If you will draw their Lewis structures for H2S and H2O, we can see that there are two lone pairs in the central atoms. Based on the molecular geometry table (see reference), both of them have 2 bonding electron pair and 2 lone pairs. They both fall to the group which have the shape bent.

What shape is H2S?

bent
The molecular shape of hydrogen sulfide is bent. The central atom sulfur is bonded to two hydrogen atoms.

Why is CH4 a tetrahedral shape?

For methane all of the four valence orbitals are bonding orbitals, and these are arranged around the carbon in the geometry that MINIMIZES electronic interaction, and this geometry is tetrahedral…with each [math]∠H-C-H=109.5°[/math].

What is the shape of the CH4 molecule explain why?

The methane molecule is tetrahedral. The central atom is carbon and there are four hydrogens attached at 109.5o angles to each other. Remember, molecules are 3D and the hydrogens are as far apart as possible in space so their electrons’ repulsion is minimized.

What type of bonds are in methane?

Methane, CH4, is a covalent compound with exactly 5 atoms that are linked by covalent bonds. We draw this covalent bonding as a Lewis structure (see diagram). The lines, or sticks, as we say, represent the covalent bonds. There are four bonds from a central carbon (C) linking or bonding it to four hydrogen atoms (H).

Why methane has a tetrahedral shape?

Methane has four C-H bonds. The four C-H bonds in methane are held at an angle of 109∘-28′ because this is the only angle in space at which repuslions between the four shared pairs of electrons is minimum. That is why methane assumes tetrahedral geometry.

Why does silane have a higher bond length than methane?

This occurs because the longer bond length reduces effective orbital overlap between the atomic orbitals making up silane, and this weakens the Si-H bonds . In methane, the carbon and hydrogen atoms overlap very well, and produce substantially strong C-H bonds.

What are the similarities between SiH4 and CH4?

First, we look at the two molecules, SiH4 and CH4. Both are tetrahedral molecules, with simple Si-H or C-H bonds that are all equivalent to each other. In silane, the bond length is 1.485 angstroms long, while methane has bond lengths of 1.092 angstroms. Both molecules have the same 109.45 degrees angle between each H-Si-H or H-C-H set of atoms.

What is the molecular orbital description of bonding in methane?

The molecular orbital description of bonding in methane does several things for us. It should reconcile our valence-bond idea of electrons localized between carbon and hydrogen with the “delocalized” picture typical of the MO approach.

What are simple molecular orbitals?

Simple Molecular Orbitals – Sigma and Pi Bonds in Molecules An atomic orbital is located on a single atom. When two (or more) atomic orbitals overlap to make a bond we can change our perspective to include all of the bonded atoms and their overlapping orbitals.