Identify each of the following energy exchanges as primarily heat or work and determine whether the sign of δe is positive or negative for the system.
a. sweat evaporates from skin, cooling the skin. (the evaporating sweat is the system.)
b. a balloon expands against an external pressure. (the contents of the balloon is the system.)
c. an aqueous chemical reaction mixture is warmed with an external flame. (the reaction mixture is the system.)

In an effort to address concerns about global warming, a power plant in portland,oregon is designed to take all of its exhaust gases from its boilers and recycle the co2 using the solvay process to make sodium hydrogen carbonate. the reaction is shown below. nh3(g) + h2o(l) + co2(g) + nacl(aq) → nahco3(aq) + nh4cl(aq) how many liters each of nh3 and co2 (both at stp) would be consumed to produce 3.00 kg of sodium bicarbonate? the volume of both nh3 and co2 would be

The molality of calcium chloride (cacl2) in an aqueous solution is 2.46 m. what is mole fraction of the solute?

The last few miles of the marathon are the most difficult for heather, her hair plastered to her head, sweat clinging to her arms, and her legs already feeling as if they had nothing left, just dead weight. after grabbing a cup of ice water, she feels the ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. in these last few miles, the breeze kicks up and she finally feels some coolness against her skin. drips of sweat, once clinging to her forehead, now spill down, and heather feels more pain as the sweat flows into her eyes.which of the following is the most likely reason why the ice struck heather’s nose when she took a drink? a) water can function as a solvent. b) water can store large amounts of heat. c) water can moderate temperatures through evaporative cooling. d) the density of water decreases when it freezes. e) water has a cohesive nature.sweat remained on heather’s forehead and arms because of the a) high salt content of sweat b) cohesive nature of water c) ability of water to moderate heat d) high evaporative cooling effect of water e) ability of water to act as a solvent