C) A battery of emf, E drives a current of 0.25A when connected to a 5.5ohms resistor. When the 5.5ohms resistor is replaced with a 2.5ohms resistor, the current flowing becomes 0.5A.
Using E=V+Ir, Find the emf, E of the battery.

b) mutualism

hope this : )

the dissolution of polymer can be thermodynamically described in 2 steps.

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.