In a pypothetical reaction `X rarr Y` , the activation are 15 and `9 "kJ mol"^(-1)` respectively. The potential energy of X is `10 "kJ mol"^(-1)`

Options

A. The threshold energy of the reaction is 25 kJ
B. The potential energy of Y is 16 kJ
C. Heat of reaction is 6 kJ
D. The reaction is endothermic

Answer

A, B, C, D

Explanation

`E_("act")("Forward")=15 "kJ mol"^(-1)`
`E_("act")=("Backward")=9 "kJ mol"^(-1)`
`E_(th) = E_("reactant")+E_("act")("Forward")`
`= 10 "kJ mol"^(-1) + 15 "kJ mol"^(-1)`
`=25 "kJ mol"^(-1)`
`E_("product")=E_(th)-E_("act")`(Backward)

`=25 "kJ mol"^(-1) - 9 "kJ mol"^(-1)`
`= 16 "kJ mol"^(-1)`
`Delta E = E_("products")-E_("reactants")`
`=(16 - 10)"kJ mol"^(-1) = 6 "kJ mol"^(-1)`
As `Delta E (or Delta H)` is +ve, the reaction is endothermic.