be set free, and how many degrees rise of temperature will result?

$101.$ a$.$ Calculate the heat content $($above $0C.)$ of $15kg.$ of tin $($a$)$ sold, just at the melting point; $(b)$ molten, just at the melting point; $(c)$ at a temperature of $1200C.$

b$.$ Calculate the heat content $($above $0C.)$ of $1$mol of silicon vapor at $3700C.($the temperature of the electric arc between carbon electrodes$).$

$102.$ A coal$-$burning furnace was used for melting copper cathodes and required $7hr.$ to melt $160$ metric tons of copper. The calorific power of the coal used was $5,952$ Cal. per kilogram. There was used $250kg.$ of coal per ton of copper melted. The heat capacity of the gases resulting from burning $1kg.$ of the coal is $4\mathrm{.}071+0\mathrm{.}000669t.$ The furnace is equipped with a waste$-$heat boiler; temperature of the gases at the entrance to the boiler, $1100C$; at exit from boiler, $500C.$

Required: $1.$ The quantity of heat required to melt the copper

$2.$ The thermal efficiency of the furnace during the melting.

$3.$ The boiler horsepower developed by the boller, assuming that it utilizes $94$ per cent of the heat dropped by the gases in passing through it$.$