What is the purpose of an indicator in the solution with the unknown concentration? select one: a. it tells when the equivalence point is obtained. b. it tells when there is enough base in the solution c. it tells when there is enough acid in the solution.

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

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

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .