Consider 100 moles of a gas stream containing 15 mol% cs2, 18 mol% o2, and 67 mol% n2. the gas is fed to a continuous absorption tower, where it contacts liquid benzene, which absorbs cs2, but not o2 or n2. benzene is fed to a column in a 2: 1 mole ratio to the feed gas. some of the benzene entering as liquid evaporates and leaves the top of the tower as vapor. the gas leaving the absorber contains 2 mol% cs2 and 2 mol% benzene. how many independent material balances can you write?

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.