Question

A 360-g piece of rebar (a steel rod used for reinforcing concrete) is dropped into 425 g of water at 24.0 °C. The final temperature of the water was measured to be 42.7 °C. Calculate the initial temperature of the piece of rebar. Assume the specific heat of steel is approximately the same as that for iron (0.449 J/gºC) and that all heat transfer occurs between the rebar and the water (there is no heat exchange with the outside environment. Specific heat capacity for water = 4.184 J/g.C)

Answer 1

The initial temperature = 248 °C.

Step-by-step explanation:

The final temperature of the water is 42.7 °C, and assuming all heat transfer occurs between the rebar and the water, we can calculate the initial temperature of the rebar.

Using the formula Q = mcΔT, where Q is the heat transfer, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature, we can set up an equation:

= (0.449 J/g °C) * (360.0 g) * (42.7 °C - Ti,rebar)

= (4.184 J/g°C) * (425 g) * (42.7 °C - 24.0 °C)

Solving this equation gives Ti,rebar = 248 °C, so the initial temperature of the rebar was 248 °C.