You convulse. Your stomach does its best to excrete it from your tract. You won't die, you do eat the remnants of it everyday after all.
There were two Ajax. Ajax Oileades and Ajax the greater.
When odysseus recieves the armor Ajax gets jealous, but Odysseues needed it more. Ajax dies during the battle in which the armor is used.
Nothing happens
you die
pain
You Die
You can get chemical burns along your throat and stomach if you swallow lye.
You burp bubbles
you ll get badly sick and might wanna go to the doctor
It depends on how much you swallow. If it is a large amount, you could get diarrhea and/or vomit.
This too will pass.