A chemical reaction takes place at 20 degrees Celsius. what is this temperature in kelvins?

To get the temperature in kelvin, just add 273 to the degrees in celcius. Therefore, 20C would be 293 degrees kelvin. (20+273=293)

To get the temperature in celcius from kelvin, just subtract 273 degrees from the degrees in kelvin. Therefore, 278K would be 5C. (278-273=5)

Absolute zero is 0 degrees kelvin or - 273C.