Can someone please help me with this chemistry problem?

Question

(a) A piston at 8.3 atm contains a gas that occupies a volume of 3.5 L. What pressure would have to be placed on the piston to force the volume to adjust to 1.52 L?
_____ atm

(b) A piston at -34.0°C contains a gas that occupies a volume of 2.5 L. To what temperature would the gas have to be heated to increase the volume to 6.2 L at constant pressure?
____°C

(c) A piston at 6995 torr contains a gas that occupies a volume of 4.7 L. What pressure would have to be placed on the piston to force the volume to adjust to 0.56 L?
_____ atm

Answer 1

Idea gas law

PV = nRT

P = Pressure
V = Volume
n= number of moles
R = Idea gas constant (Look it up)
T = temp in K

a) ok you know the pressure and volume.
you can assume that the temp and the number of moles are
going to be the same at the end.

So P1V1 = P2V2
now sub in what your know and rearrange.
P1=8.3 atm V1 = 3.5L and V2 = 1.52L

b) As P and n and R are the same

PV = nRT
P/nR =T/V
now T1/V1 = T2/V2
or T1V2 = T2V1
Sub in what you know T1 = -34 C (but in kelvin), V1 = 2.5L
V2 = 6.2 L

c) You can assume n R and T are the same.
again

P1V1 = P2V2
Sub in what you know

P1 = 6995 torr, V1 = 4.7L and V2 = 0.56 L

Now you can go do the maths

Answer 2

These are variations on pV= nRT calcs.
1. Since T and n are constant, pV= constant. So p1V1= p2V2. You have pl, V1 and V2
2. Here, p and n are constant, so V/T = constant
Then V1/T1 = V2/T2. You have V1, T1 and V2.
Remember that temps need to be in deg K.
3. The same deal as (a). After you solve the equation, though, your answer will be in torr, so you have to convert to atm (760 torr= 1 atm)

Answer 3

use the Ideal Gas Law.

PV/T= Constant


http://solospirit.wustl.edu/solospirit2/education/Science%20Side/pvt.html

this can help you.