In converting copper matte, the chemical action in each of the two stages is represented by the following equations:

$($a$)2$FeS$+3O_2=2$FeO$+2S{O}_2.$

$($b$)C{u}_{2}S+O_2=2Cu+S{O}_2.$

Assume that the average temperature in the converter during the first stage is $1100C,$ and during the second stage $1200C.$ The air, however, is blown in cold; assume that its temperature is $0C.$ Calculate for the reaction only, disregarding the nitrogen, which does not appear in the reaction.

Required: $1.$ The heat of the first reaction, all components except oxygen being at $1100.$

$2.$ The same for the second reaction, all components except oxygen being at $1200C.$b