The second answer is not a characteristic because compounds don’t vary from sample to sample. For example NaCl (table salt) is indistinguishable from sample to sample.
The answer to this ? is true
Answer:
a.
△H=−72 kcal
The energy required for production of 1.6 g of glucose is [molecular mass of glucose is 180 gm]
b.

The iron(III) ions and chloride ions remain aqueous and are spectator ions in a reaction that produces solid barium sulfate.
The correct answer is c. Temperature is the average kinetic energy of a sample so if two samples have the same temperature they will also have the same average kinetic energy. I hope this helps. Let me know if anything is unclear.