In a heat pump, heat from the outdoors at -2.42 degrees C is transferred to a room at 30.8 degrees C, with energy being supplied by an electric motor. How many joules of heat will be delivered to the room for each joule of electric energy consumed (ideally)

The value of heat transfer to the room = 9.145 J

Explanation:

Temperature of the room ()  = 30.8 degree = 303.8 kelvin

Temperature of the Surrounding () = - 2.42 degree = 270.58 kelvin

Electrical energy consumed (W) = 1 J

Heat transfer to the room is given by the formula =

⇒ = × W

Put all  the values in the above formula we get

⇒ = × 1

⇒ = 9.145 J

This is the value of heat transfer to the room.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g