Question

Express the following Kelvin temperatures in degrees Celsius: (a) \(273 \mathrm{~K}\) (b) \(100 \mathrm{~K}\)

Short answer

(a) 273 K = -0.15 °C, (b) 100 K = -173.15 °C.

Step-by-step solution

Understand the Kelvin to Celsius Conversion Formula

The formula to convert a temperature from Kelvin to Celsius is \( C = K - 273.15 \), where \( C \) is the temperature in degrees Celsius and \( K \) is the temperature in Kelvin.

Calculate the Celsius Temperature for 273 K

Substitute \( K = 273 \) into the conversion formula. Thus, \( C = 273 - 273.15 = -0.15 \). Therefore, 273 K is equal to -0.15 °C.

Calculate the Celsius Temperature for 100 K

Substitute \( K = 100 \) into the conversion formula. Thus, \( C = 100 - 273.15 = -173.15 \). Therefore, 100 K is equal to -173.15 °C.

Key concepts

Temperature Conversion

Temperature conversion is the process of changing the measurement of temperature from one scale to another. The most commonly used temperature scales are Celsius, Fahrenheit, and Kelvin. Each has its own use cases, whether it be in scientific, medical, or everyday contexts. Making these conversions is critical because each scale is used in different parts of the world for various applications.

When converting between temperature scales, it’s important to use the correct formulas to ensure accuracy. For conversion between Kelvin and Celsius, the formula is straightforward, \[C = K - 273.15\]where:

• \( C \) is the temperature in degrees Celsius
• \( K \) is the temperature in Kelvin

For example, to convert 273 Kelvin to Celsius, substitute into the formula: \[C = 273 - 273.15 = -0.15\]Thus, 273 K equals -0.15 °C. Conversions like these are essential for scientific calculations that require precision and conformity unit standards.

Kelvin Scale

The Kelvin scale is an absolute temperature scale used extensively in the scientific field. Unlike Celsius or Fahrenheit, it doesn’t use the degree symbol and starts at absolute zero - the point where molecular motion stops. This scale ensures a unique scientific accuracy and is pivotal in physics and chemistry.

Kelvin is primarily used for:

• Scientific measurements: Ideal in labs for measuring absolute temperatures.
• Understanding thermodynamic temperature, as it directly relates to kinetic energy in a system.
• Ensuring universal consistency in scientific work across various fields.

Importantly, Kelvin and Celsius scales differ in only their starting points. Each increment is equivalent between the two: 1 Kelvin change is the same as a 1-degree change in Celsius. Thus, the formula for converting Kelvin to Celsius remains a vital tool for applying the Kelvin scale in practical terms.

Celsius Scale

The Celsius scale is a temperature scale based on the freezing and boiling points of water. Known also as the centigrade scale, 0 °C corresponds to the freezing point, and 100 °C corresponds to the boiling point of water at sea level.

The Celsius scale is used extensively in everyday life for:

• Weather forecasting: Most countries report temperatures in Celsius.
• Cooking and baking: Recipes often refer to Celsius for oven temperatures.
• Healthcare: Body temperature is commonly measured in Celsius internationally.

What makes the Celsius scale convenient is its intuitive nature because it aligns closely with the physical properties of water, which is fundamental to life and scientific exploration. Understanding this scale is vital for interpreting scientific data, meteorological reports, and everyday situations where temperature is a crucial factor.