### Video Transcript

What is the boiling point of water in degrees Fahrenheit?

Okay, so to answer this question, one way to do it is to simply remember what the boiling point of water is in degrees Fahrenheit. However, let’s quickly think back to another temperature scale, the Celsius scale, which is very inherently linked to the substance that is a water. This is because the Celsius scale was devised so that zero degrees Celsius was set to be the melting point of water. That is when ice turns to liquid water and the 100 degrees Celsius was said to be the boiling point of water. That is when liquid water turns into steam. So with that in mind, we know that the temperature in the Celsius scale of the boiling point of water is 100 degrees Celsius. However, we want the boiling point of water in degrees Fahrenheit.

So to do this, we need to recall the conversion between the Celsius scale and the Fahrenheit scale. Let’s recall then that any temperature in Fahrenheit, which we’ll call 𝑇 subscript F, is equal to nine over five multiplied by the temperature in degrees Celsius, which is 𝑇 subscript C, plus 32. So say, for example, we want to find the temperature in Fahrenheit of the boiling point of water.

Well then, the formula on the left tells us that this is equal to nine over five multiplied by the temperature in Celsius of the boiling point of water plus 32. And we already know what the temperature in Celsius of the boiling point of water is. It’s 100. Therefore, substituting in 100 for the boiling point of water in degrees Celsius, we find that the temperature in Fahrenheit of the boiling point of water is nine over five multiplied by 100 plus 32.

Evaluating the right-hand side of this equation, we find that the temperature in Fahrenheit of the boiling point of water is 212 degrees Fahrenheit.