The volume of a gas at 5.0 atm is 3.5 L. What is the volume of the gas at 7.0 atm at the same temperature?

Yep, the answer is 2.5L

2.5 L.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and T are constant, and have two different values of V and P:

P₁V₁ = P₂V₂

P₁ = 5.0 atm, V₁ = 3.5 L.

P₂ = 7.0 atm, V₂ = ? L.

∴ V₂ = P₁V₁/P₂ = (5.0 atm) (3.5 L) / (7.0 atm) = 2.5 L.