PE Diagrams Practice

For a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is equal to the

• heat of fusion

• heat of reaction

• activation energy of the forward reaction

• activation energy of the reverse reaction

For a given chemical reaction, the addition of a catalyst provides a different reaction pathway that

• decreases the reaction rate and has a higher activation energy

• decreases the reaction rate and has a lower activation energy

• increases the reaction rate and has a higher activation energy

• increases the reaction rate and has a lower activation energy

If each interval on the axis labeled “Potential Energy (kJ/mol)” represents 10. kJ/mol, what is the heat of reaction?

• 60

• 20

• 30

• 40

Which balanced equation represents an endothermic reaction? (hint: look at Table I!)

• C(s) + O₂(g) → CO₂(g)

• CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l)

• N₂(g) + 3H₂(g) → 2NH₃(g)

• N₂(g) + O₂(g) → 2NO(g)

Which statement correctly describes the energy changes that occur in the forward reaction?

• The activation energy is 10. kJ and the reaction is endothermic.

• The activation energy is 10. kJ and the reaction is exothermic.

• The activation energy is 50. kJ and the reaction is endothermic.

• The activation energy is 50. kJ and the reaction is exothermic.

CH₄(g)+2O₂(g)→2H₂O(g)+CO₂(g) + heat

Which statement is true about energy in this reaction?

• The reaction is exothermic because it releases heat.

• The reaction is exothermic because it absorbs heat.

• The reaction is endothermic because it releases heat.

• The reaction is endothermic because it absorbs heat.

N₂(g) + O₂(g) → 2 NO(g)

Which potential energy diagram best represents the reaction? (hint: look at Table I)

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