If 125 gram of 75% pure Caco3 is treated with 100 gram of Hcl to produce Cacl2 H20 and Co2 Find which one is limiting reactant​

In a heat engine of 1000 j of heat enters the system and the piston does 500 j of work what is the final internal energy of the system if the inital energy was 2000 j we have to do all of these down here 1)write the equation 2)list out your know variables 3)plug the numbers into the equations 4)solve 5)write your solution statemtn that includes inital energuy and final energuy added