What is the name for the point at which the indicator changes color in a titration?

What does x represent in the formula for the compound xcl4?

All of the following are part of the biosphere except

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