Is there a limit to how long a packet could be used

yea, normally the anhydrous form of a hydrate readily reacts with any moisture in the environment, releasing lots of heat in the process.  

as the anhydrous absorbs the moisture in the environment to the point that it is fully hydrated, it will no longer take in moisture.

Yes there’s a limited time for the usage of packet

It depends on what kind of packet it is thermosetting or thermoplastic

the answer is: they rebelled against saddam hussein’s rule.

kurds opposed saddam rule and wanted independence. kurds in the north and shiites in the south revolt against hussein.

for example, the halabja attack in 1988 conducted against the kurdish people by the iraqi regime under saddam hussein, where between 4000 people are killed and around 9000 are injured.