Question

A 7.0 L sample of gas begins at 2.5 atm and 320. K. What is the new pressure if the temperature is changed to 273 K and the volume remains constant at 7.0 L?

Answer 1

2.1 atm

Step-by-step explanation:

We are given the following variables to work with:

Initial pressure (P1): 2.5 atm

Initial temperature (T1): 320 K

Final temperature (T2): 273 K

Constant volume: 7.0 L

We are asked to find the final pressure (P2). Since volume is constant, we want to choose a gas law equation that relates initial pressure and temperature to final pressure and temperature. Gay-Lussac's law does this:

`(P_(1))/(T_1) =(P_(2))/(T_2) \\`

We can rearrange the law algebraically to solve for
`P_(2)`.

`{P_(2)} =((T_2)(P_(1) ))/(T_1) \\`

Substitute your known variables and solve:

`P_2 = (273K(2.5atm))/(320K) = 2.1 atm`