MCQ
The reaction $\ce{2A(g)\rightarrow A2(g)},$ will be spontaneous :
- AAt high temperature
- ✓At low temperature
- CAt all temperature
- DNever at any temperature
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Step $I\,\,:$ ${H_2}O(g)\, \to \,H(g)\, + \,OH(g)\,;$ $\Delta H = 498\,kJ\,mol^{-1}$
Step $II\,\,:$ $OH(g)\, \to \,H(g)\, + \,O(g)\,;$ $\Delta H = 428\,kJ\,mol^{-1}$
The bond enthalpy of the $O-H$ bond is....$kJ\,mol^{-1}$
$Image$
The observed pattern of electrophilic substitution can be explained by
$(A)$ the steric effect of the halogen
$(B)$ the steric effect of the tert-butyl group
$(C)$ the electronic effect of the phenolic group
$(D)$ the electronic effect of the tert-butyl group