Question

How much heat in kJ will be absorbed by a 25g piece of aluminum as it changes temperature from 25 to 76°C:

a. Use the specific heat formula
b. Apply the first law of thermodynamics
c. Employ the heat transfer equation
d. Use the calorimetry equation

Answer 1

The heat absorbed by a 25g piece of aluminum as it changes in temperature from 25 to 76°C is 1.1475 kJ, using the specific heat capacity formula Q = mcΔT.

Step-by-step explanation:

To calculate the heat absorbed by a 25g piece of aluminum as its temperature changes from 25 to 76°C, you need to use the specific heat capacity formula. The specific heat capacity of aluminum is 900 J/kg°C. The heat transfer equation we'll use is Q = mcΔT, where Q is the heat absorbed, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.

First, convert the mass of aluminum from grams to kilograms: 25g = 0.025 kg. Then, calculate the change in temperature: ΔT = 76°C - 25°C = 51°C. Now substitute these values into the equation:

Q = (0.025 kg)(900 J/kg°C)(51°C) = 1,147.5 J

To express this in kilojoules (kJ), divide by 1000:
Q = 1.1475 kJ. Therefore, the heat absorbed by the aluminum piece is 1.1475 kJ.