Question

State the boiling point of water on the following temperature scales: (a) Fahrenheit (b) Celsius (c) Kelvin

Short answer

Water boils at 212°F, 100°C, and 373.15 K.

Step-by-step solution

Understanding the Boiling Point

The boiling point of water is the temperature at which it changes from a liquid to a gas. This temperature is a fixed point for each scale when measured at sea level.

Boiling Point in Celsius

In the metric system, water boils at 100 degrees Celsius. This is the standard boiling point which is used as a reference in many scientific contexts.

Converting Celsius to Fahrenheit

To convert degrees Celsius to Fahrenheit, use the formula: \[ F = rac{9}{5}C + 32 \]Substitute 100 for \( C \), since water boils at 100°C: \[ F = rac{9}{5} imes 100 + 32 = 180 + 32 = 212 \]. Thus, the boiling point of water in Fahrenheit is 212°F.

Boiling Point in Kelvin

Kelvin is a thermodynamic temperature scale where 0 K is absolute zero. To convert Celsius to Kelvin, use the formula: \[ K = C + 273.15 \]Since water boils at 100°C: \[ K = 100 + 273.15 = 373.15 \].Thus, the boiling point of water in Kelvin is 373.15 K.

Key concepts

Temperature Scales Conversion

Understanding temperature scale conversion is crucial as it allows you to express the same thermal quantity in different units. This is particularly useful in scientific contexts where temperature is measured using various scales. Temperature scales such as Celsius, Fahrenheit, and Kelvin are commonly used worldwide. Each scale presents a unique perspective.

• Celsius: Often used in scientific settings, Celsius sets the freezing point of water at 0°C and the boiling point at 100°C under standard atmospheric pressure.
• Fahrenheit: Predominantly used in the United States, the Fahrenheit scale sets the freezing point of water at 32°F and the boiling point at 212°F.
• Kelvin: The Kelvin scale is primarily used in scientific calculations and sets its zero point at absolute zero, making it an absolute measurement scale. It is crucial for thermodynamic computations, where 0 K is the coldest possible temperature.

These conversions allow for seamless communication and understanding across disciplines and nations that might use different temperature scales.

Celsius to Fahrenheit

Converting temperatures from Celsius to Fahrenheit is a common practice, especially for those traveling between regions that use different scales. The formula for this conversion is: \[ F = \frac{9}{5}C + 32 \] Where \( F \) represents degrees Fahrenheit and \( C \) represents degrees Celsius. This formula accounts for the difference in the size of the degree units and offsets the starting points on both scales.
**Example**:If the Celsius temperature is 100°C, which is the boiling point of water, then substituting into the formula gives: \[ F = \frac{9}{5} \times 100 + 32 = 180 + 32 = 212 \] This means the boiling point of water is 212°F in Fahrenheit. Converting is simple when using this formula and aids in easily understanding temperatures in diverse settings.

Celsius to Kelvin

The conversion from Celsius to Kelvin is straightforward, as it only involves adding a constant value. The formula is: \[ K = C + 273.15 \] Here, \( K \) indicates kelvin and \( C \) denotes degrees Celsius. This formula emerges from the definition of the Kelvin scale, where one Kelvin degree incrementally matches one degree of Celsius but starts from absolute zero rather than the freezing point of water.
**Example**:For water's boiling point expressed in Celsius degrees as 100°C: \[ K = 100 + 273.15 = 373.15 \] Therefore, in Kelvin, the boiling point is 373.15 K. This conversion is crucial for scientific calculations where temperatures at a molecular level, such as reactions and thermodynamic studies, are required.

Thermodynamic Temperature Scale

The thermodynamic temperature scale, primarily represented by Kelvin, provides a scientific model to measure temperature reflecting the absolute absence or presence of thermal energy. Unlike Celsius and Fahrenheit which are relative scales, Kelvin is absolute, starting from 0 K, known as absolute zero, where there is no thermal motion of particles.
Key Features of the Kelvin Scale:

• Absolute Zero (0 K): The point where particles theoretically stop moving and possess no thermal energy.
• Unit Relation: One Kelvin degree is equivalent to one degree Celsius increment, yet the scales are inherently different.
• Scientific Relevance: Used widely in physics and chemistry to calculate and report absolute temperatures, enabling universal comparability.

Understanding and using the thermodynamic scale is integral for accurate scientific measurements and explanations, especially in fields that explore the laws of thermodynamics and energy transformations.