Answer:
25kJ
Explanation:
Given the initial energy to be 30kJ
The energy change from the initial energy to the peak energy = (65-30) kJ
= 35kJ
since the second energy change was a drop in energy it is regarded negative
= (55-65)
= -10kJ
Therefore total energy change
= (35-10)kJ
= 25kJ
The concentration of a substance is the quantity of solute present in a given quantity of solution.
The appropriate answer is a. it involves a change in the molecular structure of the substance. A change in phase or state is referred to as a physical change. For example...liquid water freezing is a physical change because the state changes but solid water is still H20. Separating water into its constituent atoms, hydrogen and oxygen is a chemical change because the molecular structure of water is now non existent.
