The correct option is
B −4.606calGiven,
Angle the line makes with the horizontal=45∘
Therefore, slope of the line m=tan45∘=1 ...(i)
Now, we know that
ΔG∘=ΔH−TΔS∘
⇒−2.303RT(logK)=△H−TΔS∘
Simplifying the above expression, we get
⇒logK=−ΔH2.303RT+TΔS∘2.303RT
Simplifying the equation further and writing it in the form of equation of a line we get,
⇒logK=−ΔH2.303R(1T)+ΔS∘2.303R
Comparing the above equation with the general equation of a straight line y=mx+c , we get
m=−ΔH2.303R
Also, from equation (i) we get
m=1 , therefore we get 1=−ΔH2.303R
Substituting the value of R=2 , we get ΔH=−2.303(2)=−4.606cal
Therefore, the correct answer will be option B