What is inorganic phosphate and where does it come from?

Why does temperature remain same during melting while all the ice change into water?

Two pots are identical, except that in one case the flat bottom is aluminum and in the other it is copper. each pot contains the same amount of boiling water and sits on a heating element that has a temperature of 159 c. in the aluminum pot, the water boils away completely in 354 s. (a) find the time it takes the water in the copper-bottom pot to boil away completely. (in seconds)

Do enzymes absorb excess heat so that reactions occur at low temperatures?