3,953 views
35 votes
35 votes
What is the final temperature resulting when 25.0 kj of heat are added to a 550.0 g bar of iron at 25.0 celsius? The specific heat of iron is 0.449 J/ g celsius.

What is the final temperature resulting when 25.0 kj of heat are added to a 550.0 g-example-1
User Robbmj
by
3.1k points

1 Answer

9 votes
9 votes

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.

User Tarlen
by
3.0k points