A vessel contains 1.6 g of dioxygen at STP (273.15K, 1 atm pressure). The gas is now transferred to another vessel at constant temperature, where pressure becomes half of the original pressure. Calculate

Question

Philoid · Accepted Answer

(i) The given vessel contains 1.6g of dioxygen i.e. O₂ gas at STP. Therefore it contains 1.6/32 = 0.05mol of O₂. At STP, 1 mol of O₂ has 22.4L of volume, hence at 0.05mol, O₂ has 0.05 x 22.4 = 1.12L volume.

We consider Boyle’s Law, where pressure is inversely proportional to volume of the gas. Therefore, P₁V₁ = P₂V₂.

Here, V₁ = 1.12L, V₂ = ?, P₁ = 1 atm, P₂ = 0.5 atm.

V₂ = 1 x 1.12/0.5 = 2.24L.

Hence, volume of the new vessel is 2.24L.

(ii) No. of molecules in 1 mol of O₂ = 6.023 x 10²³

Therefore, no. of molecules in 0.05 mol of O₂ = 0.05 x 6.023 x 10²³

= 3.011 x 10²².

A vessel contains 1.6 g of dioxygen at STP (273.15K, 1 atm pressure). The gas is now transferred to another vessel at constant temperature, where pressure becomes half of the original pressure. Calculate(i) volume of the new vessel.(ii) number of molecules of dioxygen.

A vessel contains 1.6 g of dioxygen at STP (273.15K, 1 atm pressure). The gas is now transferred to another vessel at constant temperature, where pressure becomes half of the original pressure. Calculate
(i) volume of the new vessel.

(ii) number of molecules of dioxygen.