My iPad is dead. How can I find the spec for it via my Mac/Macbook

Look on the back of the iPad to get the serial number that's printed under word iPad, and enter it at: https://checkcoverage.apple.com

If your iPad is NOT any type of Mini iPad, the “A” model number can be found on the aluminium back of your iPad, in very small print, right under the larger bold print “iPad” on the back of the iPad.