Question

question 12 (1 point)
explosive reactions have a high activation energy and explosive substances can be safely stored for years. the potential energy diagram for these reactions is given by

all of the above diagrams represent explosive reactions

Explanation:

• For an explosive reaction, it is an exothermic reaction (\(\Delta_{rxn}H<0\), products have lower potential energy than reactants).
• The first diagram: It shows \(E_{a}(fwd)\) (forward - activation energy), \(E_{a}(rev)\) (reverse - activation energy) and \(\Delta_{rxn}H\) (negative as product energy is lower than reactant energy).
• The second diagram: Incorrectly labels \(\Delta H\) (should be \(\Delta_{rxn}H\)) and has an incorrect \(E_{a}\) (activation energy is the energy from reactant to the peak, not from product to peak for the forward reaction in an exothermic case).
• The third diagram: Has \(\Delta_{rxn}H\) positive (endothermic as product energy is higher than reactant energy), so it is wrong.
• The fourth diagram: Does not label \(E_{a}(fwd)\) and \(E_{a}(rev)\) (for a reversible reaction, both forward and reverse activation energies should be labeled when relevant).

Answer:

The first diagram.