a$.$ Antimony ore containing $27$ per cent $S{b}_2{S}_8$ is roasted, producing $S{b}_2{O}_3$ and $S{O}_2.$ The weight of ore treated is $5,000lb.$

Required: $1.$ The volume of oxygen required, in cubic feet.

The quantity of heat evolved, in pound$-$calories.

b$.$ An electric furnace is used to manufacture gaseous carbon bisulphide through the reaction of sulphur with carbon. The production is $7$ metric tons in $24$ hours.

Required: The total amount of energy evolved or required $($which$?)$ in the reaction, in Calories, and the power in kilowatts.

$100.$ An electric furnace is supplied with CaO and $,$ in the proportions to form $Ca{C}_2$ :

$Ca{O}^{*}+3$@${?}^{*}=CO+Ca{C}_2.$

It produces $0\mathrm{.}25kg.$ of per kilowatt$-$hour. The reacts with $H_{2}O$ according to the reaction

Required: $1.$ The minimum power to produce $1$ ton of per hour.