For the chemical equilibrium,
`CaCO_(3)(s) hArr CaO(s)+CO_(2)(g)`
`Delta_(r)H^(ɵ)` can be determined from which one of the following plots?

Options

A.
B.
C.
D.

Answer

A

Explanation

For the given reaction, ` K_(p) = p_(CO_(2)) or p_(CO_(2))//p^(@)`
`(p^(@) " = Reference pressure of 1 atm )`
According to van't Hoff equation ,
` (d 1n K_(p))/(dT)= (Delta H^(@))/(RT)+2`
` :. 1n K_(p) = -(Delta H)^(@)/(RT)+ I`
` (2*303 log p_(CO_(2)))/P^(@) = -(DeltaH^(@))/(RT) + I`
Hence , plot of log `p_(CO_(2))//p^(@)` versus 1/T will be a stright line with a negative slope .