Skip to main content
Ch.5 - Thermochemistry
Chapter 5, Problem 49b

(b) The specific heat of aluminum is 0.9 J/(g - K). Calculate its molar heat capacity.

Verified step by step guidance
1
Determine the molar mass of aluminum, which is approximately 26.98 g/mol.
Understand that the specific heat capacity (c) is given in J/(g\cdot K), which means it is the energy required to raise the temperature of 1 gram of the substance by 1 Kelvin.
Recognize that molar heat capacity (C) is the energy required to raise the temperature of one mole of a substance by 1 Kelvin.
Use the formula for molar heat capacity: C = c \times molar mass. Here, c is the specific heat capacity and the molar mass is the mass of one mole of the substance.
Substitute the values into the formula: C = 0.9 \, \text{J/(g\cdot K)} \times 26.98 \, \text{g/mol}.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
53s
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Specific Heat Capacity

Specific heat capacity is the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius (or one Kelvin). It is a material-specific property that indicates how much energy a substance can store per unit mass. In this case, aluminum has a specific heat of 0.9 J/(g·K), meaning it requires 0.9 joules of energy to increase the temperature of one gram of aluminum by one Kelvin.
Recommended video:
Guided course
02:19
Heat Capacity

Molar Heat Capacity

Molar heat capacity is the amount of heat required to raise the temperature of one mole of a substance by one degree Celsius (or one Kelvin). It is calculated by multiplying the specific heat capacity by the molar mass of the substance. For aluminum, to find its molar heat capacity, we need to use its specific heat and the molar mass, which is approximately 27 g/mol.
Recommended video:
Guided course
02:19
Heat Capacity

Conversion from Specific Heat to Molar Heat Capacity

To convert specific heat capacity to molar heat capacity, the formula used is: Molar Heat Capacity = Specific Heat Capacity × Molar Mass. This relationship allows us to express the heat capacity in terms of moles rather than grams, which is particularly useful in chemical reactions and thermodynamic calculations. For aluminum, this conversion will yield the molar heat capacity in J/(mol·K).
Recommended video:
Guided course
02:19
Heat Capacity
Related Practice