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AP EAMCET202316 May 2023Morning ShiftChemistryThermodynamics (C)Actual

When ' X ' g of graphite is completely burnt in a bomb calorimeter in excess of O ₂ at 298 ~K and 1 ~atm pressure as given in the equation C (graphite) + O ₂( ~g ) CO ₂( ~g ) The temperature of calorimeter raised from 298 ~K to 302 ~K . If the heat capacity of the calorimeter and molar enthalpy change for the reaction at 1 ~atm and 298 ~K are 20.7 ~kJ ~K ⁻¹ and -248.4 ~kJ ~mol ⁻¹ , ' X ^ in g is

Options

  1. A8
  2. B2
  3. C3
  4. D4

Correct answer

D. 4

Step-by-step solution

Heat released in the reaction with ' X ' g carbon Q = C _ P T =(20.7)(4)=82.8 ~kJ 1 mole or 12 ~g of carbon (graphite) gives 248.4 ~kJ heat ' X ' g carbon gives 82.8 ~kJ heat X= 12 82.8 248.4 =4 ~g

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