Question

Acetylene gas, c2h2 is used for welding. a 5 liter supply of acetylene being stored at -23 °c, exerts a pressure of 5 atm. at what temperature would the same number of moles of acetylene, moved to a 10 liter container, produce a pressure of 2 atm

Answer 1

T₂(°C) = 200 K = - 73°C.

Step-by-step 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 is constant, and have different values of P, V and T:

(P₁V₁T₂) = (P₂V₂T₁)

• Knowing that:

P₁ = 5.0 atm, V₁ = 5.0 L, T₁ = -23°C + 273 = 250 K,

P₂ = 2.0 atm, V₂ = 10.0 L, T₂ = ??? K,

• Applying in the above equation

(P₁V₁T₂) = (P₂V₂T₁)

∴ T₂ = (P₂V₂T₁)/(P₁V₁) = (2.0 atm)(10.0 L)(250 K)/(5.0 atm)(5.0 L) = 200 K.

∴ T₂(°C) = 200 K - 273 = - 73°C.