Bond Energy Calculations

2N₂ + 3H₂ --> 2NH₃ + 46 kJ
How much energy would be produced if only 1 mol of nitrogen was reacted?

• 92 kJ

• 0.143 kJ

• 23 kJ

• 15 kJ

Tags

NGSS.HS-PS3-1

C₂H₄(g) + H₂(g)   ->   C₂H₆(g)  ∆H°=-137 kJ mol^-1
Which statement about this information is correct?

• The total energy of the bonds broken in the reactants is greater 
  than the total energy of the bonds 
  formed in the product 

• The bonds broken and the bonds made are of the same strength 

• The total energy of the bonds broken in the reactants is less than the total energy of the bonds formed in the product 

• No conclusion can be made about the sums of the bond enthalpies in the product compared with the reactants 

Tags

NGSS.HS-PS1-4

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

For the reaction 2H₂(g) + O₂(g) → 2H₂O(g) the bond enthalpies (in kJ/mol) are H-H = x, O=O = y, O-H = z Which calculation will give the value, in kJ/mol, of ΔH for the reaction?

• 2x + y - 2z

• 4z - 2x - y

• 2x + y - 4z

• 2z - 2x - y

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

• -184 kJ/mol

• -92 kJ/mol

• +184 kJ/mol

• +92 kJ/mol

Tags

NGSS.HS-PS1-4

Which of the following statements is true about bond energy?

• Bond energy is the energy required to break one mole of bonds in gaseous molecules.

• Bond energy is the energy released when one mole of bonds is formed in gaseous molecules.

• Bond energy is the energy required to break one mole of bonds in liquid molecules.

• Bond energy is the energy released when one mole of bonds is formed in liquid molecules.

• -802 kJ/mol

• -1646 kJ/mol

• +802 kJ/mol

• +1646 kJ/mol

Tags

NGSS.HS-PS1-4

• 348 kJ/mol

• 368 kJ/mol

• 388 kJ/mol

• 408 kJ/mol

Tags

NGSS.HS-PS1-4

In a bond energy calculation, which factor is NOT considered?

• The type of bonds present in the reactants and products.

• The number of moles of each substance.

• The temperature at which the reaction occurs.

• The bond energies of the reactants and products.

Tags

NGSS.HS-PS1-4