question_answer

Given that                 \[2C(s)+2{{O}_{2}}(g)\to 2C{{O}_{2}}(g);\,\,\Delta H=-787\,kJ\]                 \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\to {{H}_{2}}O(l);\,\,\Delta H=-286\,kJ\]                 \[{{C}_{2}}{{H}_{2}}(g)+2\frac{1}{2}{{O}_{2}}(g)\to 2C{{O}_{2}}(g)+{{H}_{2}}O(l);\,\Delta H=-1301\,kJ\]                 Heat of formation of acetylene is [KCET 1989; Orissa JEE 2005]

A)                 \[-\,1802\,kJ\]  

B)                 \[+\,1802\,kJ\]

C)                 \[-800\,kJ\]        

D)                 \[+228\,kJ\]