Bond Energy and Enthalpy

Question 1

What is bond energy?

• AEnergy released when a bond forms
• BEnergy required to break one mole of a particular bond
• CEnergy stored in the nucleus
• DEnergy required to melt a substance

Question 2

What happens to energy when a chemical bond is broken?

• AEnergy is released
• BEnergy is absorbed
• CNo energy change occurs
• DEnergy is converted into mass

Question 3

What happens to energy when a chemical bond is formed?

• AEnergy is absorbed
• BEnergy is destroyed
• CEnergy is released
• DTemperature always decreases

Question 4

Which equation is used to calculate enthalpy change from bond energies?

• AΔH = bonds formed + bonds broken
• BΔH = bonds broken − bonds formed
• CΔH = bonds broken × bonds formed
• DΔH = bonds formed ÷ bonds broken

Question 5

If 500 kJ is absorbed to break bonds and 700 kJ is released when new bonds form what is ΔH?

• A+1200 kJ
• B+200 kJ
• C−200 kJ
• D−1200 kJ