Bond Enthalpies

Does breaking bonds require energy, release energy, or not involve energy at all?

• requires energy to break

• releases energy when broken

• No energy involved

Tags

NGSS.HS-PS1-4

Which statement is FALSE for an endothermic reaction?

• Products higher in energy and less stable

• Reactants lower in energy and more stable

• Products have stronger bonds than reactants

• Reactants have stronger bonds than products

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Bond making and bond breaking. Which of following is TRUE?

• During bond breaking, heat is absorbed

• During bond making, heat is absorbed

• During bond breaking, heat is released

• None of the above

Tags

NGSS.HS-PS1-4

Using the table of average bond energies below the image, the ΔH for the reaction in kJ is.....

• + 160 kJ

• -63 kJ

• - 160 kJ

• -217 kJ

Tags

NGSS.HS-PS1-4

Tags

NGSS.HS-PS1-4

Using the reaction & table above, determine the change in energy and whether or not the reaction is endothermic or exothermic:

• -2054 kJ endothermic

• 2045 kJ endothermic

• -2045 kJ exothermic

• 2045 kJ exothermic

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

How much energy is required to break all of the bonds in the first molecule depicted in the reaction above? (you must include the proper sign for credit)

Tags

NGSS.HS-PS1-4

Tags

NGSS.HS-PS1-4

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

The average bond enthalpies for O-O and O=O are 146 and 496 kJ/mol respectively. What is the enthalpy change, in kJ, for the reaction below?

H-O-O-H(g) → H-O-H(g) + ½O=O(g)

• -102

• +102

• +350

• +394

Tags

NGSS.HS-PS1-4