STP stands for Standard Temperature and Pressure. It is defined as 273K at 1 atmosphere pressure. All temperatures used in problems with gasses must use the Kelvin (absolute) temperature scale. To convert from degrees C to degrees Kelvin, remember "K is C plus 273" (degrees C + 273 = K) 1 atmosphere of pressure can also be expressed as 101.3 Kilopascals, or 760mmHg (millimeters of mercury).

Your turn! For each of the following convert the temperature to K, or change the pressure units as indicated.

Change:	to:	Check your answer
35°C	K	Interactive popup. Assistance may be required. Check Your Answer 308K
-25°C	K	Interactive popup. Assistance may be required. Check Your Answer 248K
1.3 atm	mmHg	Interactive popup. Assistance may be required. Check Your Answer 98 mmHg
400 mmHg	atm	Interactive popup. Assistance may be required. Check Your Answer 0.53 atm