gases, volume, pressure... help!!! i dont know anything!?

Question

5. A sample of gas occupies 1.55 L at 27oC and 1.00 atm pressure. What will the volume be if the pressure is increased to 50.0 atm, but the temperature is kept constant?


6. A sample of nitrogen gas occupies 1.55 L at 27oC and 1 atm pressure. What will the volume be at -100oC and the same pressure?


7. A 1.0 L volume of gas at 27oC exerts a pressure of 85.5 kPa. What will the pressure be at 127oC? Assume constant volume.


8. A sample of nitrogen has a volume of 275 mL at 273K. The sample is heated and the volume becomes 325 mL. What is the new temperature in kelvins?


9. A small cylinder of oxygen contains 300.0 mL of gas at 15 atm. What will the volume of this gas be when released into the atmosphere at 0.900 atm?

Answer 1

Let me first ask if you have been going to class and reading your book while this material was being covered?

For all of these kinds of problems, you can use the equation:

P1V1/T1 = P2V2/T2

Wher P1 V1 and T1 are the pressure, volume and temperature in the first set of conditions, and P2, V2 and T2 are the pressure, volume and temperature in the second condition.

If one of the conditions doesn't change (for example, temperature in the first question), then that variable just goes away.

Just plug in the values you have and solve for the one you need to find.

Answer 2

5...Boyle's Law.
P1 x V1 = P2 x V2
1.55 ÷ 5 = 0.31 atm.

6....Charle's Law.
V1 x T2 = V2 x T1
V2 = (1.55 x 173) ÷ 300 = 0.89 L

7...Gay Lussac's Law.
P1 x T2 = P2 x T1
85.5 x 400 = P2 x 300
P2 = 34,200 ÷ 300 = 114 kPa

8....Charle's Law.
T1 x V2 = T2 x V1
273 x 325 = T2 x 275
T2 = 88,725 ÷ 275 = 322.6 K

9....Boyle's Law.
P1 x V1 = P2 x V2
V2 = 15 x 300 ÷ 0.9 = 4,500 ÷ 0.9 = 5,000 mL dispersed to atmosphere.