Help with an ideal gas law problem...

A gas sample in a syringe has a volume of 35.26 mL at 0.9854 atm. The plunger of the syringe is depressed such that the volume of the syringe is reduced to 22.33 mL. What is the new pressure in the syringe assuming there has been no change in temperature?



For this problem, would I cross multiply to get .6240 or do I solve it a different way?

Hi KG!

Boyle's law is used to predict the result of introducing a change, in volume and pressure only, to the initial state of a fixed quantity of gas.

The before and after volumes and pressures of the fixed amount of gas, where the before and after temperatures are the same

P1*V1 = P2*V2

Covert from mL to Liter

1000 mL = 1 L

35.26 mL = 35.26/1000 = 0.03526 L
22.33 mL = 22.33/1000 = 0.02233 L

Data:

V1 = 0.03526 L
P1 = 0.9854 atm

V2 = 0.02233 L
P2 = X atm

T = constant

P1*V1 = P2*V2

(0.03526*0.9854) = X*0.02233

(0.03526*0.9854) = X*0.02233

0,0347 = X*0.02233

Solve for X

X = 0,0347/0.02233 = 1.55 atm

Answer:

The new pressure in the syringe is 1.55 atm

Bye from Italy,

C6H6

My signature:

Asking is legitimate and choosing the Best Answer is good manners. Thank you.

Given the ideal gas equation
PV = nRT
n, R, and T are constant so…
P1V1 = P2V2
Your final answer is..
P2 = (P1V1)/V2

-edit-
You do not need to convert any units.

(0.9854*35.26)/22.33 = 1.5559876
With 4 sig figs
P2 = 1.556 atm