Question

For the reaction `H_(2)(g) + I_(2)(g)hArr2HI(g)K_(c) = 66.9` at `350^(@)C` and `K_(c) = 50.0` at `448^(@)C` . The reaction has
A. `DeltaH=+"ve"`
B. `DeltaH=-"ve"`
C. `DeltaH="zero"`
D. `DeltaH "sign can not be determined"`

Answer 1

Correct Answer - B
`H_(2)(g)+I_(2)(g)hArr2HI(g)`
`"log"(K_(2))/(K_(1))=(DeltaH)/(2.303R)[(1)/(T_(1))-(1)/(T_(2)) : "log" (50)/(66.9)=(DeltaH)/(2.303R)[(1)/(623)-(1)/(721)]`
After calculation negative value of `DeltaH` is obtained.