Question

A 1.50-liter sample of dry air in a cylinder exerts a pressure of 3.0 atmospheres at a temperature of 25°C. Without change in temperature, a piston is moved in the cylinder until the pressure in the cylinder is reduced to 1.0 atmosphere. What is the volume of the gas? (Be sure to use the correct number of significant figures.) 0.22 L 0.50 L 2.0 L 4.5 L

Answer 1

Answer:

4.5 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 different values of P and V:

(P₁V₁) = (P₂V₂)

• Knowing that:

P₁ = 3.0 atm, V₁ = 1.5 L,

P₂ = 1.0 atm, V₂ = ??? L.

• Applying in the above equation

(P₁V₁) = (P₂V₂)

∴ V₂ = (P₁V₁)/P₂ = (1.5 L)(3.0 atm)/(1.0 atm) = 4.5 L.

So, the right choice is: 4.5 L.