The diagram and data below represent gas and the conditions of pressure, volume, and temperature of the gas in a rigid cylinder with a moveable piston. Determine the volume of the gas in the cylinder at STP.

2.3 L

Explanation:

when you have this eqaution you use P1V1T2=P2V2T1.

since you are looking for volume of gas cylinder that means you are looking for V2.

so you have your given P= 1.0 atm, V=2.5L, T=298K.

They ask you to use STP or standard pressure and temperature.

STP P= 1atm, STP T=273 K

so you are looking for V2 meaning you are going to get V alone so your new equation is P1*V1*TS/ P2* T1= V2

so you now substitue so its now 1*273*2.5/ 1* 298= V

682.5/ 298= V

Lastly V= 2.2902 and you round to tenths so now you have

V= 2.3 L

answer; i believe that the correct answer is (a) potassium(k)