Which of the following is the BEST evidence of a chemical change? 1.Two liquids forming layers instead of mixing.
2.Two liquids mixing to produce a precipitate.
3.Two liquids mixing to blend their colors.
4.Two solids forming a mixture.

No link answers please!

What amount of heat is exchanged when 106.2 grams of substance y goes from a liquid at 35 degrees celsius to a solid at the same temperature? melting point of substance y = 35 degrees c; δhvaporization = 3.67 j/mol; δhfusion = 3.30 j/mol. mwsubstance y = 28.22 g/mol. −12.4 j −3.51 x 102 j 1.24 x 101 j 351 j