Can alkenes be cracked or only alkanes can be cracked? Then what would the products be? Like for alkanes a alkenes must always be formed but what about for alkenes cracking? Also, when we boil salt water its temperature is 101.4 degrees. But when performing fractional or simple distillation why dots the reading at the thermometer be 100 degrees even though the boiling point is 101.4? Thanks for the help guys!