Can a non-polar molecule contain polar bonds? explain your answer with an example.

Yes

Explanation:

It is possible that a non polar molecule contain polar bonds.

Consider the example of CO₂:

In carbon dioxide the atoms are arranged in angle of 180 degree and molecule is linear. So in this way the net dipole movement becomes zero and molecule is non polar.

But when we see the electronegativity of both bonded atoms the oxygen is more electronegative than carbon. The oxygen atom have partial negative charge and carbon have partial positive charge because shared pair of electron is more attracted towards the oxygen. Thus bond become polar because one end is partial positive and other is partial negative. Thus a non polar carbon dioxide molecule have polar bond.

A non-polar molecule may contain polar bonds because polarity also has to do with the geometry of the molecule.

A polar bond is one in which electron density is unevenly distributed between the bonding atoms due to significant difference in electronegativity between the covalently bonded atoms.

The presence of polar bonds does not automatically mean that the molecule will be polar. A polar molecule must be asymmetrical. No symmetrical molecule is polar even it has polar bonds. Assymmetrical means that the molecule does not have an axis of symmetry

For instance, CF4 has four polar C-F bonds but it is not polar because the compound is symmetrical and the polar bonds cancel out. The resultant dipole moment of the molecule is zero. The same can be said about CO2, BF3 etc.

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c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.