Question

23.0 g of copper pellets are removed from a 300∘C oven and immediately dropped into 120 mL of water at 25.0 ∘C in an insulated cup. *What will the new water temperature be?

Answer 1

The energy amount going from the metal is equal to the energy amount going to the cool water is given by

Heat lost(Metal) = Heat gain (water)

m₁. C_p . ₁ = m₂. C_p . 2

23. 0.385.(300-x) = 120. 4.184. (x-25) , (120mL=120g density of water is 1gm/CC )

Where, x is final temperature, specific heat taken in J per gram degree celsius.

(115.5 - 0.385 x) = (120/23) . ( 4.184 x - 104.6)

(115.5 - 0.385 x) = 5.21. ( 4.184 x - 104.6)

115.5 - 0.385 x = 21.79 x - 544.96

x= 30.855C is final temperature of water.