Posted by Harry on .
A sample of oxygen gas occupies 500.0 mL at -185°C and 75.0 cmHg. Calculate the temperature in °C if the gas has a volume of 221.0 mL at a 55.0 cmHg.
PV/T remains constant, so
(75.0)(500)/(-185+271) = (55)(221.0)/T
T = 28°K
Note that we don't really have to convert to L and Pa, because the same conversion factors would be applied to both sides of the equation. The only wrinkle is the °C-°K conversion, because that is additive, not multiplicative.
This answer is not correct
Steve gave you the combined gas law, but it seems that you were confused. The gas law is as followed:
Solve for T2:
T2=[88K*(55.0 cmHg*221.0mL)/(75.0 cmHg*500.0 mL)
Convert Kelvin to Celsius:
28.6-273=-244 º C <== Three significant figures