MCQ
An elementary particle is
- AAn element present in a compound
- BAn atom present in an element
- ✓A sub-atomic particle
- DA fragment of an atom
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$(i)\, 6C(s) + 3H_2(g) \to C_6H_6(l) ; \Delta H = +45.9\,kJ$
$(ii)\, H_2(g) +\frac {1}{2}O_2(g) \to H_2O(l) ; \Delta H = -285.9\,kJ$
$(iii) \,C(s) + O_2(g) \to CO_2(g) ; \Delta H = -393.5\,kJ$
.....$kJ$


[Given : molar mass of $Br _2=160\,g\,mol ^{-1}$
atomic mass of $C =12\,g\,mol ^{-1}$
atomic mass of $Cl =35.5\,g\,mol ^{-1}$
density of dibromine $=3.2\,g\,cm ^{-3}$
density of $\left.CCl _4=1.6\,g\,cm ^{-3}\right]$