The heat of combustion of carbon to C O 2 is - 393 . 5 kJ / mol . The heat released upon the formation of 35…

The heat of combustion of carbon to CO2 is -393.5 kJ/mol. The heat released upon the formation of 35.2 g of CO2 from carbon and oxygen gas is
  1. -315 kJ
  2. +315 kJ
  3. -630 kJ
  4. -3.15 kJ

Solution

Formation of CO2 from carbon and dioxygen gas can be represented as
Cs+O2(g)→CO2(g) ;∆fH=-393.5 kJ mol-1
(1 mole=44 g)
The heat released on formation of 44 g CO2
=-393.5 kJ mol-1
=-393.5 kJ mol-144 g×35.2 g
=-315 kJ

Asked in: NEET 2015 (Phase 2)

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