Question

500 L of a gas at 300 K and 700 Torr would occupy what volume at STP.

Answer 1

• According to the conditions of the question we should make up two equations of Mendeleev-Clapeyron, which characterize the initial and final state for this gas:

$p(1) • V(1) = \nu • R • T(1)$

$p(2)•V(2)=ν•R•T(2)$

• Further, by dividing the first equation by the second, we obtain ($\nu$ and R are constants):

$(p(1) • V(1))/ (p(2) • V(2)) = T(1)/T(2) \to$

$V(2) = (p(1) • V(1) • T(2)) / (p(2) • T(1))$

• Considering that: 700 Torr = 93326 Pa, STP : p = 10⁵ Pa, T = 273 K, Pa=N/m², L = m³, we will get:

V(2) = (93326(N/m²) • 5•10³(m³) • 273(K)) / (10⁵(N/m²) • 300(K)) = (127389990•10³) / (300•10⁵) = 424633.3•10^-2 = 4246.3 m³ = 4246.3 L

Answer: V(2) = 4246.3 L