An ionic compound has a slightly negative heat of solution in water. would you expect it to be soluble or insoluble in water?

What reaction is taking place? 02 + c3h8 = h20 + co2

Choose an equation that represents an enzyme-catalyzed reaction. (a) enzyme + substrate → enzyme-substrate complex (b) enzyme + substrate ←−→ enzyme + products (c) enzyme + substrate ←−→ enzyme-substrate complex → enzyme + products (d) enzyme + substrate ←−→ enzyme-substrate complex → enzyme-substrate complex + products

What physical property of gold makes panning a useful way to get gold from streams?