Connaught Rangers didn't have any 'Pals' battalions, there were no Pals brigades. If you have his service number (should be easy to find if he was killed in action as will be on the Commonwealth War Graves website), if you go on Ancestry his service record, as someone KIA, should be there, and when you find out what Battalion he was in, the war diary with the National Archives will tell you what they were doing on that date