In an ovan , due to insufficient supply of oxygen, 60% of the carbon is converted to carbon dioxide wehreas the remaining 40% is converted into carbon monoxide. If the heat of combustion of carbon to CO_(2)is 394kJ mol^(-1) while that of its oxidation to CO is 111 kJ mol^(-1), calculate the total heatproduced in the oven by burning 10 kgof coal containing 80% carbon by weight .Also calculate the efficiency of the oven.

In an ovan , due to insufficient supply of oxygen, 60% of the carbon i

1.	In an ovan , due to insufficient supply of oxygen, 60% of the carbon is converted to carbon dioxide wehreas the remaining 40% is converted into carbon monoxide. If the heat of combustion of carbon to CO_(2)is 394kJ mol^(-1) while that of its oxidation to CO is 111 kJ mol^(-1), calculate the total heatproduced in the oven by burning 10 kgof coal containing 80% carbon by weight .Also calculate the efficiency of the oven.
Answer» Solution :The reactions taking place in the oven are `C(s) + O_(2)(g) rarr CO_(2)(g) + 394KJ mol^(_1)` `C(s) + (1)/(2) O_(2)(g) rarr CO(g) + 111kJ mol^(-1)` Carbon present in 10 kg coal `= (80)/( 100) xx 10 kg= 8 kg` Carbon converted to `CO_(2)= ( 60)/( 100) xx 80 kg= 4.8 kg ` Carbon converted to `CO = ( 40)/( 100 ) xx 8 kg = 3.2 kg` 12 g. i.e., 0.012kg of carbon on COMBUSTION to `CO_(2)` produce heat `= 394 kJ` `:. ` 4.8kg of carbon on oxidation to `CO_(2)` produce heat`= ( 394)/( 0.012) xx 3.2 = 157600 kJ` 0.012kg of carbon on oxidationto CO produce heat `= 111kJ` `:.` 3.2 kg of carbon on oxidation to CO will produce heat `= ( 111)/( 0.012) xx 3.2 kJ = 29600 kJ` `:. ` Total heat produced `= 157600+ 29600 = 1,87,200 kJ` If oven were `100%` efficient, all carbon would have been converted to `Co_(2)` Heat produced from 8 kg carbon would have been`= ( 394)/( 0.012) x 8 =262,667kJ` `:. ` % efficiency `= ( 187,200)/( 262,667)xx 100= 71.3 %`