[Korokian]

N₂O₄(g) ---> 2NO₂(g)
constant temperature
starting pressure of N₂O₄(g) is 0.100 atm
after some time the pressure increases from 0.100 atm to 0.148 atm.
partial pressure of N₂O₄?

[Borek]

Over 80 posts already and you still don't know you have to try by yourself first?

[Korokian]

i do try it first.. don't you know that i post because i need help? or are you just going to keep criticizing me?
i don't know how to start, why else would i post here....

okay let me state the obvious borek

total pressure= p1 + p2
PV=nRT
........you going to help or just keep saying try by yourself first

[Borek]

total pressure= p1 + p2
PV=nRT

Can you calculate initial n(N₂O₄) from these equations and data given in the question?

[Korokian]

you know that 1 mol N2O4(g) makes 2 mol NO2(g)
but you don't have the volume or temperature
temperature is constant but you still don't have volume

[Korokian]

i did .148/ 3
and got the partial pressure of N2O4 to be .049333 atm

[Borek]

No, you are on the wrong track.

Try to assume you start with 1 mole of N₂O₄ - that will give you initial n and V.

If so T & R are just constants so you don't have to think about them.

[Korokian]

so initial mol is 1 mol
initial V would be 10 L

final V is 10 L
final P is .148 atm
final mol is 1.48 mol?

and 1.48 / 3 ?

[Borek]

so initial mol is 1 mol
initial V would be 10 L

Huh? 1 mol of gas at STP is 22.4L, you have 10 times lower pressure, so the volume must be 10 times that.

[Korokian]

so then initial volume is 224 L

i really don't see where this is going

[Borek]

What will be amount of BOTH gases after n moles of N₂O₄ decomposes?

Try with 0.1 mole if n doesn't work for you.

[Korokian]

.1-x + 2x mols

[Borek]

OK, now that you know total number of moles you can calculate both total pressure and partial pressure of N₂O₄. Rest should be easy