$5.-$ Assuming ideal gas behavior, calculate the heat that must be transferred

in each of the following systems. Remember to sketch the system

and the B$.$E$.$

I. A stream of N$2$ flowing at a rate of $100$ mol$|/$min is heated

$20\backslash$deg C to $100\backslash$deg C$.$

II$.$ The N$2$ contained in a $5$L reactor at an initial pressure of $3$ bar is cooled from

$90\backslash$deg C to $30\backslash$deg C

III. A water$-$methanol mixture of volume $20$L is heated or cooled to $25\backslash$deg C

up to a temperature of $120\backslash$deg C$.$ Note The methanol fraction corresponds to

$44.$