Question

1.9 kg block of iron at 24 °C is rapidly heated by a torch such that 14 kJ is transferred to it. What temperature would the block of iron reach (assuming the complete transfer of heat and no loss to the surroundings)? If that same amount of heat (14 kJ ) was quickly transferred to a 810 g pellet of copper at 24 °C, what temperature would the copper reach before it begins losing heat to the surroundings?

Cs, Fe(s)= 0.450 J/g*C
Cs, Cu(s)= 0.385 J/g*C

Answer 1

For iron, T2 = 40.4 degree C

For copper, T2 = 68.89 degree C

Step-by-step explanation:

For iron:

m = 1.9 kg, T1 = 24 C, Q = 14 kJ = 14000 J, c = 0.450 J / g C = 450 J / Kg C

Let T2 be the final temperature of iron.

Q = m x c x (T2 - T1)

14000 = 1.9 x 450 x (T2 - 24)

T2 = 40.4 degree C

For copper:

m = 810 g = 0.81 kg, T1 = 24 C, c = 0.385 J/ g C = 385 J / Kg C, Q = 14 KJ

Let T2 be the final temperature of copper

Q = m x c x (T2 - T1)

14000 = 0.81 x 385 x (T2 - 24)

T2 = 68.89 degree C