In the diagram above , the activation energy for the backward reaction is

Derek644222

2 years ago

forward reaction is always
Reactants→Products
and in an energy profile diagram the reactants is always by the left side while the product is by the right side

so the reactants (left side) in this profile diagram is 10kJ where the line P2 + Q2 started while the product (right side) is 15kJ i.e in between 20kj and 10kj where the line 2PQ ends

and the activation energy is always at the end point of the Bell shaped energy diagram which in this case is 40kj

so now when looking for the Activation energy (Ae) for the forward reaction in "ANY" energy profile diagram
note that it is always Activation energy (Ae) – Reactant
i.e in this case 40kj – 10kj = 30kj for the forward reaction
but remember we were asked fo find (Ae) of the backward reaction which will now be

Activation energy - product note this implies for any backward reaction in any profile diagram o
i.e 40kj – 15kj = 25kj
so the correct answer is undoubtedly option C

Hope this helps

montty

10 years ago

The ans is =40-15=+25kj option C

Danielogo

7 years ago

energy profile diagram activation energy for backward reaction

Siko

4 years ago

pls where do we get our 15 ?

Niyi465

1 month ago

it is meant to be d

regony600

9 years ago

The answer is D. 40-10=30

Ref New school chemistry pg 254