Video Transcript
A gas, which starts at a temperature of 280 kelvin, is heated by 80 kelvin. What is the final temperature of the gas in degrees Celsius?
Here, we’re going to be thinking about converting between two temperature scales, Kelvin and Celsius. To do this, it will be helpful to recall that the magnitude of one kelvin is equivalent to that of one degree Celsius and that in order to convert a value in kelvin to Celsius, we simply subtract 273. Now we know the gas has an initial temperature of 280 kelvin. We can choose to go ahead and convert this to Celsius using the formula below, which says that the temperature in Celsius equals the temperature in kelvin minus 273. Thus, 280 kelvin minus 273 gives a result of seven degrees Celsius. This is the initial temperature of the gas.
We’ve been told that the gas is then heated by 80 kelvin, and we wanna know its final temperature. Remember though that because of this relationship that we established earlier, a temperature increase of 80 kelvin is equivalent to a temperature increase of 80 degrees Celsius. Thus, if we choose to do the addition while still working in terms of kelvin, we have 280 kelvin plus another 80 kelvin for a final temperature of 360 kelvin. But we could also choose to do the addition working in terms of Celsius. So we have seven degrees Celsius plus 80 degrees Celsius, which gives us a final temperature of 87 degrees Celsius.
We can do one last thing to check our work by comparing the final temperature in kelvin and degrees Celsius, again, using this formula boxed in down below. The temperature in degrees Celsius should equal the temperature in kelvin minus 273. And indeed, 360 kelvin minus 273 gives a result of 87 degrees Celsius. This is the final temperature of the gas.
