Aheat pump is used to heat a house in the winter and to cool it in the summer. during the winter, the outside air serves as a low-temperature heat source; during the summer, it acts as a high-temperature heat sink. the heat-transfer rate through the walls and roof of the house is 0.75 kj s—l for each c of temperature difference between the inside and outside of the house, summer and winter. the heat-pump motor is rated at 1.5 kw. determine the minimum outside temperature for which the house can be maintained at 200c during the winter and the maximum outside temperature for which the house can be maintained at 250c during the summer.

= -4.2°C

= 49.4°C

Explanation:

A Carnot cycle is known as an ideal cycle in thermodynamic. Therefore, in theory, we have:

|| =

Similarly,

|| = || + ||

During winter, the value of || = 20°C = 273.15 + 20 = 293.15 K and || = 1.5 kW. Therefore,

|| = 0.75( -  )

Similarly,

|| = 1 -

1.5/0.75*(293.15-) = 1 - (/293.15

Further simplification,

= -4.2°C

During summer, = 25°C = 273.15+25 = 298.15 K, and || = 1.5 kW. Therefore,

|| = 0.75( -  )

Similarly,

|| = - 1

1.5/0.75*( - 298.15) = (/298.15

Further simplification,

= 49.4°C

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.