We are going to use this equation to solve our problem:
Q = m * C * ΔT
Where Q is the heat, m is the mass, C is the specific heat and ΔT is the change in temperature.
From the given information we know:
Q = 25.0 kJ (positive because the heat is added to the iron)
m = 550.0 g
C = 0.449 J/(g°C)
ΔT = Tfinal - Tinitial = Tfinal - 25.0 °C
The heat is given in kJ and the specific heat is given in K, let's convert the heat to J. We know that there are 1000 J in 1 kJ.
1000 J = 1 kJ
Q = 25.0 kJ = 25.0 kJ * 1000 J/(1 kJ) = 25000 J
Q = 25000 J
Now we can replace the given values into the equation and solve it for Tfinal that is our unknown:
Q = m * C * ΔT
25000 J = 550.0 g * 0.449 J/(g°C) * (Tfinal - 25.0 °C)
25000 J/(550.0 g * 0.449 J/(g°C)) = Tfinal - 25.0 °C
101.2 °C = Tfinal - 25.0 °C
Tfinal = 101.2 °C + 25.0 °C
Tfinal = 126.2 °C
Answer: The final temperature is 126 °C.