Question

Consider two identical iron nails: one nail is heated to 95 °c, the other is cooled to 15 °c. the two nails are placed in a coffee cup calorimeter and the system is allowed to come to thermal equilibrium. what is the final temperature of the two nails

Answer 1

In this case, the final temperature of the two nails will be an average of their initial temperatures, which is 55 °C.

Step-by-step explanation:

When two objects at different temperatures come into contact, heat is transferred from the object with higher temperature to the object with lower temperature until they reach thermal equilibrium.

In this case, the heated iron nail at 95 °C will transfer heat to the cooled iron nail at 15 °C when they are placed in the coffee cup calorimeter.

The final temperature of the two nails will be an average of their initial temperatures, which is (95 °C + 15 °C) / 2 = 55 °C.

Answer 2

The heat released or absorbed by a substance is calculated through the equation,
H = mcpdT

where H is teh heat,
m is the mass,
Cp is the specific heat, and
dT is the temperature difference

In this item, since both nails are identical, m and cp for both nails are equal such that the equation can be expressed as,
mcp(95 - x) = mcp(x - 15)

where x is the final temperature. Solving for the value of x from the equation derived above will give us a final answer of 55 degrees C.

Answer: 55°