Question

The boiling point of diethyl ether, acetone and n-butyl alcohol are $${35}^{o}C$$, $${56}^{o}C$$and $${118}^{o}C$$respectively. Which one of the following correctly represent their boiling point in Kelvin scale.
A) 306K, 329K, 391K
B) 308K, 329K, 392K
C) 308K, 329K, 391K
D) 329K, 392K, 308K

Answer 1

Hint:Kelvin scale is defined as the absolute scale which exists the temperature which is colder than the freezing point of ice, $$0^{o}C$$ on the Celsius scale. In this scale the two fixed temperatures are taken and they are ice point $$0^{o}C$$and steam point $${100}^{o}C$$and the interval which present between them is divided into 100 equal parts. This scale was defined by Lord Kelvin in 1848 which was based on the Carnot cycle.


Complete solution:
 Each division which is present on the Kelvin scale is equal to a degree present on the Celsius scale. On the Celsius scale we see that$$0^{o}C$$ is the freezing point of water whereas in the Kelvin scale the zero point is referred to as absolute zero. The use of Kelvin scale is done for very low and very high temperatures where water is not involved.
The formula of Kelvin scale is the following
$$K{=}^{o}C+273$$
So the temperature for diethyl ether in Kelvin will be =$${35}^{o}C$$+273=308K
So the temperature for acetone in Kelvin will be = $${56}^{o}C$$+273=329K
the temperature for n-butyl alcohol in Kelvin will be = $${118}^{o}C$$+273=391K

so the correct answer for this question is option (C).


Note:Celsius scale is known as centigrade scale which was introduced by Swedish physicist known as Anders Celsius. It is based on the$$0^{o}C$$ for freezing point of water and$${100}^{o}C$$ for boiling point of water the Celsius temperature obeys the system of relative scale or interval instead of absolute system of scale. Then came the modern Celsius scale which was based on the triple point of Vienna Standard Mean Ocean Water and also on the concept of absolute zero.