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 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