ECapacitors

On what factors does Voltage rating of electrolytic capacitor depend on?
Can it be used in AC application(because reverse polarity damages the capacitor)?

It is the strength of the dielectric insulation between the plates. An electrolytic capacitor will conduct if connected backwards. That current generates heat that will quickly cause a steam explosion. Exceeding the “WVDC” rating will do the same thing by punching through the internal insulating layer allowing current to flow through the device causing heat buildup and, depending upon the size, either bang or boom.

In any case, if you abuse an electrolytic capacitor, expect flying shrapnel to be the consequences.