Which of these equations is balanced?
a. h2o co > h2co3
b. 2nacl h2so4 > na2so4 2hcl
c. 2cao h2o > ca(oh)2
d. mn fe > mns fe?

c, liquids evaporate, creating a gas

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.