The compound that does not undergo Friedel-Crafts alkylation reaction but gives a positive carbylamine test is :

For an endothermic reaction:

(A) $$\mathrm{q}_{\mathrm{p}}$$ is negative.

(B) $$\Delta_{\mathrm{r}} \mathrm{H}$$ is positive.

(C) $$\Delta_r \mathrm{H}$$ is negative.

(D) $$\mathrm{q}_{\mathrm{p}}$$ is positive.

Choose the correct answer from the options given below:

$$1.0 \mathrm{~g}$$ of $$\mathrm{H}_2$$ has same number of molecules as in:

Which of the following plot represents the variation of $$\ln \mathrm{k}$$ versus $$\frac{1}{\mathrm{~T}}$$ in accordance with Arrhenius equation?