Question

question 8 (1 point)
using the vsepr theory, predict that the shape of beryllium dihydride, beh₂.
bent
linear
regular tetrahedral
triangular planar
trigonal pyramidal
question 9 (1 point)
which of the following is a non - polar molecule?
ch₃cl
ch₂cl₂
hcl
ccl₄

Explanation:

Question 8

• VSEPR theory: The shape of a molecule is determined by the repulsion between electron - pair groups (bonding and non - bonding) around the central atom.
• For \(BeH_2\):
• The central atom is \(Be\).
• \(Be\) has 2 valence electrons.
• It forms 2 single bonds with \(H\) atoms (\(Be - H\) bonds).
• There are no non - bonding electron pairs on \(Be\).
• According to VSEPR theory, when the central atom has 2 bonding electron - pair groups and no non - bonding electron pairs, the molecular geometry is linear.

• Polarity of a molecule: A non - polar molecule has either no polar bonds or the polar bonds are symmetrically arranged so that the bond dipoles cancel out.
• \(CH_3Cl\):
• \(C - H\) bonds are less polar than \(C - Cl\) bond.
• The molecule has a tetrahedral geometry (approximate due to different substituents). The bond dipoles do not cancel out, so it is polar.
• \(CH_2Cl_2\):
• It has a tetrahedral geometry. The \(C - Cl\) bond dipoles do not cancel out (because of the non - symmetric arrangement of \(Cl\) and \(H\) atoms around \(C\)), so it is polar.
• \(HCl\):
• It has a single polar \(H - Cl\) bond. So it is a polar molecule.
• \(CCl_4\):
• It has a tetrahedral geometry.
• The \(C - Cl\) bonds are polar, but due to the symmetric tetrahedral arrangement of the four \(C - Cl\) bonds, the bond dipoles cancel out. So it is a non - polar molecule.

Answer:

linear

Question 9