I got 2 questions for ya:
1. Calculate the new pressure of an oxygen tank at 127o C if the tank had 2200 psig at room temperature (22o C)?
I used Lussac's law.
Here's my work:
P1= 2200psi
P2= X
T1= 295K
T2= 400K
(2200x295)400= X
I got 2983psi
Is that correct?
2. Given 320 mL of saturated gas at 760 mm Hg and 25o C), what would be the volume under dry conditions at the same pressure and temperature? [water vapor pressure at 25o = 23.78 mmHg]
I got sorta confused on this one but here's what I came up with.
I used the combined gas law.
P1= 760mmHg - 23.78mmHg = 736.22
**Is this correct? I was a little iffy on this figure.**
V1= 320mL
T1= 298K
P2= 760mmHg
V2=X
T2= 298K
My work: ((736.22)(320)(298))/(298x760) = 309.98 or 310mL
Hopefully I'm good on this one too.
Thanks a bunch. If anything is wrong please point it out to me.
P1= 2200psi
P2= X
T1= 295K
T2= 400K
(2200x295)400= X
I got 2983psi
and I get 2983, also, but I don't know how you got that answer with the math.
P1/T1 = P2/T2 and
P2 = (2200 x 400)/295. If I do your math it gives 1622. Hopefully, you just typed it in wrong. You know if T goes up the P must go up. Check my thinking.
The second problem looks ok to me.
Let's analyze your calculations for both questions:
1. For the first question, you are applying Gay-Lussac's Law, which states that the pressure of a gas is directly proportional to its absolute temperature, assuming the volume and amount of gas are constant. Your initial and final temperatures are both given in degrees Celsius, so you need to convert them to Kelvin by adding 273.15.
The correct setup for the problem is:
P1 = 2200 psi
P2 = X (unknown)
T1 = 22°C + 273.15 = 295.15 K
T2 = 127°C + 273.15 = 400.15 K
Now, you can use the formula P1/T1 = P2/T2 to solve for P2:
(2200 psi / 295.15 K) = (X / 400.15 K)
Cross-multiplying, you get:
(2200 psi)(400.15 K) = (295.15 K)(X)
Simplifying further, you'd find:
X = (2200 psi)(400.15 K) / (295.15 K)
After calculating this, you should get X = 2990 psi, not 2983 psi. So your answer is slightly off.
2. For the second question, you're using the combined gas law, which relates the initial and final conditions of pressure, volume, and temperature for a gas sample. Your approach seems correct, but there's one mistake in your calculation.
The correct setup for the problem is:
P1 = 760 mmHg - 23.78 mmHg = 736.22 mmHg
V1 = 320 mL
T1 = 25°C + 273.15 = 298.15 K
P2 = 760 mmHg (same as P1)
V2 = X (unknown)
T2 = 25°C + 273.15 = 298.15 K
Using the formula P1V1/T1 = P2V2/T2, you can solve for V2:
(736.22 mmHg)(320 mL) / (298.15 K) = (760 mmHg)(X) / (298.15 K)
Simplifying the equation, you'd find:
X = (736.22 mmHg)(320 mL) / (760 mmHg)
After calculating this, you should get X ≈ 309.06 mL, not exactly 310 mL. So your answer is also slightly off.
Overall, your approach to both questions is correct, but the final results have minor errors.