The development and use of the a common and important piece of laboratory equipment, led scientist to the discovery of several basic laws

The answer is the Microscope.

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.

the correct answer would be b) volume versus temperature, because they are also directly proportional.