# Video: Converting Fahrenheit Temperature to Kelvin Temperature

The boiling point of a substance is a temperature of 500Β°F. Express this as a Kelvin temperature.

02:55

### Video Transcript

The boiling point of a substance is a temperature of 500 degrees Fahrenheit. Express this as a kelvin temperature.

Okay, so in this case, weβve got a substance which has a boiling point of 500 degrees Fahrenheit. What weβre asked to do is to express this in kelvin. We can do this in two ways. Firstly, we can convert the temperature in degrees Fahrenheit to a temperature in degrees Celsius. To do this, we can use the conversion formula between Fahrenheit and Celsius. Then, once we have a temperature in degrees Celsius, we can convert it to kelvin.

The second method is to convert directly from degrees Fahrenheit to kelvin by combining the conversion formulas: the conversion formula from degrees Fahrenheit to degrees Celsius and the one from degrees Celsius to kelvin.

So the first conversion formula we need to know, π sub πΆ β the temperature in degrees Celsius β is equal to five-ninths multiplied by π sub πΉ β the temperature in Fahrenheit β minus 32. This is a conversion formula between degrees Fahrenheit and degrees Celsius. So letβs use this conversion formula and apply it to our first method.

Weβve already been given π sub πΉ β thatβs 500 degrees Fahrenheit. So we can plug that into our equation. Therefore, we find that π sub πΆ β the temperature in degrees Celsius β is equal to five-ninths multiplied by 500 minus 32, where 500 is the temperature in degrees Fahrenheit. We can evaluate this to find that π sub πΆ is equal to 260 degrees Celsius.

From here on, we need our second conversion formula: π sub πΎ β the temperature in kelvin β is equal to π sub πΆ β the temperature in degrees Celsius β plus 273. We can substitute π sub πΆ with 260. So weβve got π sub πΎ is equal to 260 plus 273. This gives us our final answer that π sub πΎ β the temperature in kelvin β is 533 kelvin. But remember we said that we can do this another way by combining the two conversion formulas that weβve written down on the right.

The second conversion formula says that π sub πΎ is equal to π sub πΆ plus 273. But we already know that π sub πΆ is all of this on the right-hand side. So we can substitute that in. We get that π sub πΎ is equal to five-ninths multiplied by π sub πΉ minus 32 and then we add 273 to it. What weβve done here is to find a direct conversion between the temperature in degrees Fahrenheit and the temperature in kelvin. This way we donβt need to go via degrees Celsius.

So essentially, the calculation is exactly the same. But whatβs changed is that we no longer need an intermediate temperature in degrees Celsius. Weβve combined the two formulas together rather than applying the formulas one by one. And so we find that π sub πΎ is equal to five-ninths multiplied by 500 minus 32 plus 273. And of course, weβve substituted 500 in for π sub πΉ.

Evaluating this, we once again find that our temperature in kelvin is 533 kelvin.