Answer:
A) Polar molecules have a non-zero net dipole moment. Both CO2 and H2O have two polar bonds. However the dipoles in the linear CO2 molecule cancel each other out, meaning that the CO2 molecule is non-polar. The polar bonds in the bent H2O molecule result in a net dipole moment, so H2O is polar.
B) In PCl5, in addition to equitorial bonds which lie in the same plane, there are axial it suffers more repulsion it is longer than the other bonds; hence PCl5 decomposes to form PCl3. So PCl5 is highly reactive. Source(s): 5 Heavy ElectroNegative atoms in One Molecule Lone Pair.
C) In h2o there is hydrogen bonding because oxygen has a high electronegativity (only second to flourine). so, the hydrogen atoms from other molecules of water forms a hydrogen bonds with oxygen resulting in intermolecular hydrogen bonding. therefore at room temperature h2o is a liquid and h2s is a gas.
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Explanation: