# The boiling point of ethanol is 78°C. What would it be in kelvin?

Mar 13, 2016

$351 K$

#### Explanation:

1. Derive formula from the following data:
Boiling Pt of water
$K = 373$
$C = {100}^{o}$
Freezing Pt of Water
$K = 273$
$C = {0}^{o}$
2. Write the ratio of the 2 temperature scales with the zero points and the unit sizes
$\frac{K - 273}{373 - 273} = \frac{C - 0}{100 - 0}$
3. Simplify
$\frac{K - 273}{\cancel{100}} = \frac{C}{\cancel{100}}$
4. 100 are cancelled since these 2 scales have same unit sizes so that the formula is;
$K - 273 = C$
5. Isolate $K$ by adding 273 both sides of the equation
$K = C + 273$
6. Plug in the given data $C = {78}^{o}$ to the derived formula
7. The answer is $351 K$