A propane tank of 1-m3 is at 150 kPa, 300K and connected by a valve to another tank of 0.5 m3 with propane at 250 kPa, 380 K. The valve is opened, and the two tanks come to a uniform state at 320 K. What is the final pressure?

Final pressure of the gas 176.55 kPa.

Explanation:

Consider propane as an ideal gas as P << critical pressure.

The ideal gas equation is:

P V = m Rₐ T

Here P is pressure, V is volume, m is mass, T is temperature and Rₐ is individual gas constant.

Rₐ =

Here R is universal gas constant and M is mass of propane gas.

Substitute 8.314 J mol⁻¹ K⁻¹ for R and 44.1 x 10⁻³ kg mol⁻¹ for M in the above equation.

Rₐ = = 188.52 J kg⁻¹ K⁻¹

According to the question,

m₁ =

Substitute 1 m³ for V₁, 150 x 10³ Pa for P₁, 300 K for T₁ and 188.52 J kg⁻¹ K⁻¹ for Rₐ in the above equation.

m₁ =

m₁ = 2.65 kg

According to the question,

m₂ =

Substitute 0.5 m³ for V₂, 250 x 10³ Pa for P₂, 380 K for T₂ and 188.52 J kg⁻¹ K⁻¹ for Rₐ in the above equation.

m₂ =

m₂ = 1.74 kg

After opening the valve, mass of the gas is:

m = m₁ + m₂ = ( 2.65 + 1.74 ) kg = 4.39 kg

Volume of the gas is :

V = V₁ + V₂ = ( 1 + 0.5 ) m³ = 1.5 m³

The temperature of the gas becomes 320 K. So, the final pressure of the gas is given by the relation :

P =

P =

P = 176.55 x 10³ Pa = 176.55 kPa  

i think it's 35 meters

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.