NEET2015ChemistryThermodynamics (C)Actual
The heat of combustion of carbon to C O 2 is   - 393 . 5   kJ / mol . The heat released upon the formation of 35 . 2   g of C O 2 from carbon and oxygen gas is
Options
- A- 315 k J
- B+ 315 k J
- C- 630 k J
- D- 3.15 k J
Correct answer
A. - 315 k J
Step-by-step solution
Formation of C O 2 from carbon and dioxygen gas can be represented as C s + O 2 ( g ) → C O 2 ( g )   ; ∆ f H = - 393.5   k J   m o l - 1 ( 1   mole = 44   g ) The heat released on formation of 44   g C O 2 = - 393.5   k J   m o l - 1 = - 393.5   k J   m o l - 1 44   g × 35.2   g = - 315   k J