I filled a Pepsi can with water and froze it. When I got it out the side of the can was split and the ice bulged out of the top. Why did this happen?

If you freeze a can of soda, it usually will not split, but the top will bulge.  The water content has frozen and expanded, but the sugary syrup has not.  It has separated from the frozen water and is under tremendous pressure.  At that point, if you pull the tab, you can see what coke syrup looks like dripping from the ceiling.