Question

When sand is coated with a layer of trimethylhydroxysilane, (ch3)3sioh, it repels water and can no longer get wet. Hydrophobic sand (aka, magic sand) is fun to play with, but it can also have useful applications in agriculture to reduce water consumption.8 predict the geometry for the silicon atom in trimethylhydroxysilane?

Answer 1

The silicon atom in trimethylhydroxysilane has a tetrahedral geometry due to its four sp3 hybridized orbitals, which are formed by bonding with three methyl groups and one hydroxyl group.

Step-by-step explanation:

The silicon atom in trimethylhydroxysilane, (CH3)3SiOH, would adopt a tetrahedral geometry. In this molecule, silicon is bonded to three methyl groups (CH3) and one hydroxyl group (OH). Since silicon is in group 14 of the periodic table, it has four valence electrons which it shares with each of the four groups attached to it, forming four sp3 hybridized orbitals. The repulsion between these electron pairs maximizes their separation, leading to a tetrahedral geometry with bond angles of approximately 109.5 degrees around the silicon atom.

Answer 2

The central atom in trimethylhydroxysilane is silicon

The number of valence electrons in silicon = 4

The hybridization can be calculated using the formula

number of total electrons = 0.5 X (number of valence electrons -(charge) + number of single bonded atoms to the central atom)

Number of total electrosn = 0.5 (4+4) = 4

hence hybridization of Si = sp3

There is no lone pair on Si

So the shape / geometry of trimethylhydroxysilane = Tetrahedral