The volume of NO₂=6.25 L
Avogadro's stated :
In the same T,P and V, the gas contains the same number of molecules
So the ratio of gas volume = the ratio of gas moles
[tex]\tt \dfrac{V_1}{V_2}=\dfrac{n_1}{n_2}[/tex]
the volume of each gas (in a container of volume 10L) :
Total mol=10+10+20=40 mol
[tex]\tt \dfrac{10}{40}\times 10=2.5~L[/tex]
[tex]\tt \dfrac{10}{40}\times 10=2.5~L[/tex]
[tex]\tt \dfrac{20}{40}\times 10=5~L[/tex]
NO₂ (has increased by 25%) :
[tex]\tt 0.25\times 5~L=1.25\\\\new~volume=5+1.25=6.25[/tex]
[tex]\tt \dfrac{10}{20}\times 6.25=3.125[/tex]
[tex]\tt \dfrac{10}{20}\times 6.25=3.125[/tex]