Question

What is the boiling point of water on the Kelvin Scale?
a.373.15 K
b.273.15K
c.373 K
d.374.15 K

Answer 1

HINT: Try and remember the conversion between a temperature in degrees Celsius to Kelvin.
After making this conversion, apply this to the boiling point of water on the degrees Celsius to convert it in Kelvins.

Complete step by step answer:
Before we solve this question, let us first get some background on the unit Kelvin and why it is called so.
Recognized worldwide as the SI Unit of Temperature, the Kelvin scale (named after thermodynamics pioneer Lord Kelvin) is defined so as to ensure that its absolute zero is considered to be at the triple point of water, the temperature where all three of forms of water exist at the same time, which has been experimentally determined to be about -273.15O C.
\[\begin{align}
  & 0K\text{ = -273}\text{.15 degrees C} \\
 & \Rightarrow \text{ 273}\text{.15 K = 0 degrees C} \\
 & \therefore \text{373}\text{.15 K = 100 degrees C (}\because \text{ Boiling point of water is 100 degrees C)} \\
\end{align}\]
Therefore, the boiling point of water is 373.15K.


NOTE:
 To answer this question correctly, it is important to both read the question clearly and to be clear conceptually about temperature scales and their conversion.
 Be very careful of the distinction between the melting and boiling points of water and do not confuse the two. And while it is often common to go by the conversion K = OC + 273, note that this relation is not accurate and that the real zero on the Kelvin scale equates to -273.15OC.