ChemB unit 3 custom test:

Question

1.)Is this question endothermic or exothermic

PCI3 (s)+CI2 (g)—> PCI5 (s) + energy

2.) Is this question endothermic or exothermic?

2KNO3 (S) + energy —>2KNO2 (s) +O2

3.) When new chemical bonds form,energy______.
Is taken into the system
Stays the same in the system
Is released from the system

4.)Does breaking bonds require energy,release energy, or not involve energy at all?
Requires energy to be absorbed into the system
No energy is involved
Releases energy when broken

5.) When solids Ba(OH)2 and NH4SCN are mixed, a solution is produced and the temperature drops. Which statement about energetics of this reaction is correct?
The reaction is endothermic and H is negative
The reaction is exothermic and H is negative
The reaction is another make an age is positive
Reaction is exothermic and H is positive

Please help, I am stuck!!

Answer 1

1. Exothermic
2. Endothermic

Answer 2

3. Is released from the system
4. Requires energy to be absorbed into the system

Answer 3

5. The reaction is endothermic and H is negative

Answer 4

oops! 5 is not answered correctly. If the solution gets colder then endothermic is right BUT when a reaction is endothermic then delta H is positive. Actually the correct answer is not listed; however, I expect answer C, which is nonsense as posted, was correct and was not typed in correctly.