212 Explain the admissibility as evidence

Explain the admissibility as evidence for each of these:

A revolver found in a home where officers were executing a search warrant that appeared valid on its face, but turned out to be invalid, through no fault of the officers.
An unlawfully obtained confession the prosecutor wants admitted at trial to show that the testifying witness (defendant who gave the confession) is lying.
In a civil, not criminal tax evasion trial, Internal Revenue Service lawyers want to introduce money against the defendant. The money was unlawfully seized from the defendant in a drug raid at his house.
Defendant was arrested in the front yard of his home, about 100 feet from his front door, after police observed him firing a weapon in the direction of a school. Without a search warrant, police officers required the defendant to go back into his house, where they searched the living room. Police found a half a kilo of cocaine under the couch.
Stolen property was found by a neighbor while snooping, on his own, in the defendant’s garage. The garage door was open while the neighbor was away from the home. Pictures of the property had been in a newspaper article about local burglaries. He took the property from the garage and turned the property over to the police. The prosecutor wants to use the stolen property to help prove the defendant is guilty of two burglaries.