My mom left me and my sister a house and my sister passed away can I sell the house

That depends.  From the way you've worded your question, I assume that your sister passed away after your mom.  If your mom left the house to your and your sister as joint tenants (which means that the house goes to the survivor), you would now own all of it.  However, if your mom left it to you and your sister as tenants in common, which is more common, it means that each of you owned half of the house, and your sister's would now pass to her heirs.  If she had a will, her half of the house would go to whomever she left it to in her will.  If not, it would pass by the laws of intestasy, and whether you would get her half of the house depends on what other relatives she left behind.  Spouse?  Children?  Other siblings? As you can see, the issue gets complicated, probably too complicated for this forum.  You may want to consult a local estate attorney.