Problem 60 - Chemistry Matter and Change

Question

Ethanol has a specific heat of 2.44 \(\mathrm{J} /\left(\mathrm{g} \cdot^{\circ} \mathrm{C}\right) .\) What does this mean?

Step-by-Step Solution

Answer

Ethanol requires 2.44 Joules to heat 1 gram by 1°C.

Step 1: Understand Specific Heat

The specific heat of a substance is the amount of heat required to raise the temperature of one gram of that substance by one degree Celsius.

Step 2: Apply Definition to Ethanol

For ethanol, having a specific heat of 2.44 J/(g·°C) means that it takes 2.44 Joules of energy to raise the temperature of 1 gram of ethanol by 1 degree Celsius.

Key Concepts

Ethanol

Ethanol, often recognized as ethyl alcohol, is a clear, colorless liquid that appears in alcoholic beverages. Beyond its role in spirits and liquors, ethanol is extensively used in chemical laboratories and industries as a solvent. It’s also a significant player in fuel and energy sectors, as it can be used as an alternative fuel or an additive to reduce emissions in gasoline.
Ethically produced by fermentation of sugars, ethanol can also be synthesized from petroleum derivatives. In the laboratory and industrial settings, ethanol's uses are vast due to its ability to dissolve both polar and non-polar substances. Given this versatility, understanding the properties of ethanol, such as its specific heat capacity, is essential for applications in science and industry.

Joules

Joules are the standard unit of energy in the International System of Units (SI). Named after physicist James Prescott Joule, one Joule is defined as the amount of energy transferred when a force of one newton moves an object one meter.
In practical terms, Joules measure different types of energy, including heat energy, which is crucial in specific heat calculations. For ethanol with a specific heat capacity of 2.44 J/(g·°C), it means 2.44 Joules of heat energy is required to raise the temperature of one gram of ethanol by one degree Celsius.

• Specific heat: Amount of energy per gram per degree Celsius.
• Energy in Joules quantifies work done or heat transferred.

This standardization helps in comparing different substances and understanding the thermal efficiency in various processes.

Temperature

Temperature is a measure of the average kinetic energy of particles in a substance. When we talk about raising the temperature of material like ethanol, we’re referring to increasing this kinetic energy.
The Celsius scale is commonly used to measure temperature changes in scientific contexts. For ethanol, a specific heat of 2.44 J/(g·°C) means that for every one degree Celsius increase, a corresponding energy input of 2.44 Joules per gram is required.

• Unit: Celsius (°C) in specific heat calculations.
• Kinetic energy: Directly relates to temperature changes.

Understanding temperature changes helps in predicting how much energy a process will consume or conserve, which is vital in designing efficient systems.

Energy

Energy is a broad concept that encompasses various forms such as kinetic, potential, thermal, chemical, and nuclear. In the context of specific heat, energy specifically refers to thermal energy - the energy that results from the movement of atoms and molecules within substances.
For ethanol, as mentioned, a specific heat of 2.44 J/(g·°C) elaborates the conversion between energy and temperature change. If you wish to increase the ethanol's temperature, you must supply energy. Conversely, removing energy will lower the temperature. This principle is central in thermodynamics and energy management.

• Thermal energy: Associated with temperature changes.
• Energy management: Critical for efficiency in heating and cooling processes.

Understanding energy's role in temperature changes allows us to effectively apply this concept in practical scenarios, from industrial processes to everyday heating tasks.