Reshma put 10 cm3 of water and 2 g of a different solid into each of four test-tubes. She shook each test-tube.
The drawings show the test-tubes after 10 minutes.

Why can the salt and sugar no longer be seen in test-tubes A and C?

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.