NY Regents Chemistry Exam June 2023, Questions 53-54
A sample of a gas in a sealed, rigid cylinder with a movable piston has a volume of 0.250 liter at STP.
53 Show a numerical setup for calculating the volume of this sample of gas at 298 K and 1.00 atm.
Solution: Let's look at Table T to choose the right equation for our problem. We are asked to calculate volume and we are given pressure and temperature. We will use combined gas to solve this.
P1V1/T1 = P2V2/T2
STP stands for standard temperature and pressure which can be found in Table A on the Reference Table.
P1= 1atm P2 = 1.00atm
V1= 0.250 V2=?
T1= 273K T2 = 298K
(1atm)(0.250)/273K = (1.00atm)(V2)/ 298K
We are asked to show the setup and do not have to actually calculate the answer.
54 State a change in pressure that will cause the gas in the cylinder to behave more like an ideal gas.
Solution: Real gas is most like ideal gas at low pressure. We can lower the pressure for the gas in cylinder to behave most like an ideal gas.