General Knowledge Questions

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.

They are the sites at which microtubules attach to chromosomes.

Fractional distillation is the process of seperation of a mixture of two or more liquids into the different fractions, which differ fairly widely in their boiling points. The liquid with a lower boiling point will be vaporized first and hence would be the distillate (first fraction). Eg. Ethyl alcohol has a boiling point of 78.10C and water 1000C. When a mixture of these two liquids is heated, alcohol vaporizes first and is collected separately as the distillate.