CO2 is a gas while SiO2 is a solid. Why ?

 hello Sana, the ans. to ur ques. is--

CO2 exists as a single molecule as it has no d-orbital . It forms p-pi_p-pi bonding  due to which it has weak van der waal forces  and  hence exist as gas at room temp.

SO2 has d-orbital & forms p-pi_d-pi bonding. It exists as bigger 3-D  network  structures & hence have stronger van der waal  forces . Therefore exist as solid at room temp.

Hope this will help u understand.

  • 127

hey thnx !!  :)

  • 2
  1. In Carbon Dioxide Carbon is bonded to 2 oxygen atoms through double bond O=C=O due to which CO 2 exists as discrete molecule. as a result of which it exists as gas and exists as monomeric units (like O=C=O) which have weak interactions between the molecules, it takes only a small amount of energy to break down the solid and it is a gas at normal temperatures and normal pressure.
  2. Silicon dioxide exists as a polymer (SiO 2 )n where n can be a large number), so lots of O-Si-O-Si-O molecules in a polymer lattice. So this as a high melting point and is a solid at normal temperature and pressure, sand being an example. In SiO 2 each Si atom tetrahedrally sorrounded by 4 oxygen atoms as shown below and hence exists as solid in 3D network.

  • 16

  1. In Carbon Dioxide Carbon is bonded to 2 oxygen atoms through double bond O=C=O due to which CO 2 exists as discrete molecule. as a result of which it exists as gas and exists as monomeric units (like O=C=O) which have weak interactions between the molecules, it takes only a small amount of energy to break down the solid and it is a gas at normal temperatures and normal pressure.
  2. Silicon dioxide exists as a polymer (SiO 2 )n where n can be a large number), so lots of O-Si-O-Si-O molecules in a polymer lattice. So this as a high melting point and is a solid at normal temperature and pressure, sand being an example. In SiO 2 each Si atom tetrahedrally sorrounded by 4 oxygen atoms as shown below and hence exists as solid in 3D network.

  • 9
What are you looking for?