A piston$-$cylinder device initially contains $0\mathrm{.}50$ kg of steam at $3\mathrm{.}5$ MPa $,$ superheated by $7\mathrm{.}4C.$ Now the steam loses heat to

the surroundings and the piston moves down, hitting a set of stops at which point the cylinder contains saturated liquid

water. The cooling continues until the cylinder contains water at $200C.$

Problem $04\mathrm{.}136.$c $-$ Find heat transfer

Determine the amount of heat transfer when the piston first hits the stops $(Q_{in},1-2).($Round the final answer to three decimal places.$)$

$($Include a minus sign if necessary.$)$

The amount of heat transfer when the piston first hits the stops is

kJ $.$

of $15$