5. We use the following relation derived in Sample Problem 21-2:
Tf "S = mc ln . Ti (a) The energy absorbed as heat is given by Eq. 19-14. Using Table 19-3, we find
J Q = cm"T = 386 (2.00 kg)(75 K) = 5.79 × 104 J kg·K where we have used the fact that a change in Kelvin temperature is equivalent to a chance in Celsius degrees. (b) With Tf = 373.15 K and Ti = 298.15 K, we obtain