Question

27.0 g of copper pellets are removed from a 300?C oven and immediately dropped into 90.0 mL of water at 22.0 ?C in an insulated cup.

What will the new water temperature be?

Express your answer with the appropriate units.

Answer 1

Heat lost by hot body is equal to heat gained by cold object

Heat lost by copper is Q = - m C ?T

                                       = - (27)(0.386)(T - 300)

                                       = (27)(0.386)(300 - T) ..........(1)

Heat gained by water is Q = m C ?T

                                         = (90)(4.186)(T -22) ..........(2)

Equating (1) & (2) , we get

              (27)(0.386)(300 - T) = (90)(4.186)(T -22)

Solving for T, we get

                  T = 29.48^oC