Consider the strengths of the following changes:
separate NaI into its ions: 702 kJ/mol
separate water into molecules 60 kJ/mol
form solvent shells around sodium ions and iodide ions 770 kJ/mol
When dissolving NaI in water, the change is likely to be (endo/exo thermic) and the reaction will feel (hot/cold) to the touch
Question 2 options:
endothermic, hot
endothermic; cold
exothermic, hot
exothermic, cold
2 answers
lets gooooooooooo
separate NaI into its ions: 702 kJ/mol
separate water into molecules 60 kJ/mol
form solvent shells around sodium ions and iodide ions 770 kJ/mol
So it takes 702 kJ/mol energy for this step + 60 kJ/mol for step 2. Then you get back 770 kJ/mol for step 3.
dH = 702 + 60 - 770 = -8 kJ/mol
That tells you that NaI dissolves in water, it is exothermic, so the vessel will feel warm.
separate water into molecules 60 kJ/mol
form solvent shells around sodium ions and iodide ions 770 kJ/mol
So it takes 702 kJ/mol energy for this step + 60 kJ/mol for step 2. Then you get back 770 kJ/mol for step 3.
dH = 702 + 60 - 770 = -8 kJ/mol
That tells you that NaI dissolves in water, it is exothermic, so the vessel will feel warm.