Chemistry question, I’ve already started it but i don’t know how to come up with the final answer. please help, i have zero points left

The volume of the gas = 9.14 L

Given

Kb = 6.3 x 10⁻⁵

2.5 L solution

pOH= 2.5

Required

Volume of gas

Solution

pOH = 2.5

For weak base :

( 3.2 x 10⁻³)² = 6.3 x 10⁻⁵  x M

M = 0.163

mol = M x V

mol = 0.163 x 2.5 L

mol = 0.408

At STP(1 atm, 273 K) 1 mol = 22.4 L

so the volume = 0. 408 x 22.4 L = 9.14 L

answer; i do believe the correct answer is (river); /// good luck