A 0.250 g sample of the weak acid HA (molar mass = 150.0 g/mol) is dissolved in 50.0 g of water. The freezing point of the resulting solution is -0.071°C. Calculate the value of Ka for this acid. Assume molality equals molarity in this solution. (Kf for water is 1.86°C/m.)

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