Question

Draw and label the energy diagram for a reaction in which ∆E = 31 kJ/mol, and Ea =
51 kJ/mol. Place the reactants at energy level zero. Give the value of ∆Eforward. ∆Ereverse, and ∆Eα
Answer in units of kJ/mol.

Answer 1

The values of  ∆Eforward = 51 kJ/mol,

∆Ereverse = 20 kJ/mol , and

∆Eα = 51 kJ/mol .

Explanation:

as the reactants are assumed to be at zero level ; E  (reactants) = 0 ,

∆Eα = Ea = 51 kJ/mol.

E(product ) =  ∆E = 31 kJ/mol

The activation energy (Ea) for the forward reaction is  shown by  

∆E for = 51 kJ mol-1.  

∆E (forward) = E (activated complex) - E  (reactants) = 51 - 0  = 51 kJ mol-1.

The activation energy (Ea) for the reverse reactionis shown by (B):

∆Ea (reverse) = E (activated complex) - E (products) = 51-31 = 20 kJ mol-1