A gas exerts a pressure of 0.5 atm at a temperature of 45 °C. What does the pressure become if the temperature is reduced to 25 °C? The volume remains constant throughout.
2007-01-21 03:30:32 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Use the gas law to realise it:
n * R * T = p * V
n is the amount of your compound in moles
R is the gaskonstant (the value is irrelevant in this prolem)
T is temperature
p is pressure
V is volume
As you see T and p are directly proportional, so if T increases 20 times, p will increase 20 times.......or more generally:
p2/p1 = T2/T1 --> p2 (the one w're looking for) = p1 * T2/T1
hence,
p2 = 0.5 atm * (273,15 +25)/(273.15 +45) = 0.469 atm
If V wasn't kept constant we would have had to calculate on that as well.
2007-01-21 04:10:52 · answer #1 · answered by Anonymous · 0⤊ 1⤋
.5/273+45 = x/273+25
x = .47 atm
You have to change the temp to Kelvins, that may be your problem
2007-01-21 11:34:33 · answer #2 · answered by Megan 2 · 0⤊ 0⤋
P1/T1 = P2/T2
0.5/(273.15+45) = P2/(273.15+25)
P2 = 0.469 atm
2007-01-21 11:36:30 · answer #3 · answered by Kemmy 6 · 1⤊ 0⤋