Thread: Chemistry... I freakin hate it

Originally Posted by sacredsarcasm

Originally Posted by Kraker Jak

Originally Posted by Kraker Jak

7

no kraker its a chemistry questions. he doesnt want to know how many STDs you have.

Originally Posted by sacredsarcasm

Originally Posted by Kraker Jak

Originally Posted by Kraker Jak

7

no kraker its a chemistry questions. he doesnt want to know how many STDs you have.

In that case....


x=8

But does D^(ST)=x?

wheres draco, something tells me this is his cup of tea...

Originally Posted by sacredsarcasm

is this HS or college chem?

anyway, let me try it. its good practice.

PITFALL: you forgot the MM of nitrogen gas is the sum of both nitrogens. you got the formula right but you forgot the MM is also 2X the mass of N. MM N2=25.0134

get rid of extra info. and it seems the problem simplifies to:

N2 solubility = 0.0150 g/L @ 1.00 atm

so we are at 1.00 atm and N2 is 0.0150 g/L soluble at this pressure. my first thought was we need more info, like the volume of the divers lungs, but since we are doing this per L it again makes it a little easier.

if the blood(water) can absorb 0.0150g/L then using the MM it can absorb 5.35 x 10^-4 mol/L.

to get the solubility at 4 atm use the gas laws. P1/n1=P2/n2. in this case we just need to multiply the 1.00 atm answer by 4, to get the 4.00 atm answer. 2.14 x 10^-3 mol/L.

looks like your problem might have been the molar mass, but also dont forget to try and see through the extra info and get rid of it so you dont get confused.

Thankyou!!!

I just went to class and talked to professor, and yes, the MM was my problem (Doh!) After working for hours on this, here's the answer.

C1/P1 = C2/P2

PURE N2 at 1.00 atm dissolves 0.0150 g/L in water(blood).

Air is 78% N2 (by moles)

C1=0.0150 g/L
P1=1.00atm

C2=?
P2=0.78atm (partial pressure of N2 is directly proportional to the Molar % (see "Air is..."))

C2 = 0.0150 * 0.78
=
0.0117 g/L

Now I need Mol

0.0117  / 28.01~ (don't need exact, +/- 2% error)
=
0.0004177 mol/L

Now I need 4x this, because it's 4x the first atm.

0.0004177 * 4
=
0.0016708 mol/L

Originally Posted by bust331

Trying to get your TTP buddies to answer it for you

Cheater

Yes.......... If you had only known the effort I put into this before posting..........





And now for PART 2!!!!!

If the diver suddenly surfaces, ___ mL of N2 gas, in the form of tiny bubbles, are released into the bloodstream from each liter of blood (at 37.0 ºC and 1 atm).

I've kinda got the idea so I'll just do my work here.

P = MRT - PV = nRT, solving for n - n = PV/RT.

P=1atm
V=1L
R=0.0821 (constant)
T=37+273=310K

(1*1)/(310*0.0821)
=
0.03929 mol N2

when dissolved in water(blood) 1g is VERY close to 1mL so... I'm thinking this
we get the grams of N2 Might be wrong...

0.03929 * 28.01~
=
1.10054g N2
=
1.10054mL N2

BUT- Lo' and behold I did something wrong  Can anyone help me out?

wait a sec....

0.0012531 mol/L (4x pressure - 1x pressure)

0.0012531 * 28.01
=
0.035099331 g/L
=
0.035099331 mL/L

BAH! Still didnt work...

Originally Posted by DJ Mr. White

But does D^(ST)=x?

epic...

God you bunch of post whores, only like 4 real posts in here :3 getting my hopes up w/ false replies

Originally Posted by Imisnew2

God you bunch of post whores, only like 4 real posts in here :3 getting my hopes up w/ false replies

but.... we wuv u.... <3

Originally Posted by Imisnew2

God you bunch of post whores, only like 4 real posts in here :3 getting my hopes up w/ false replies

Hey, listen here you maxi pad....i already told you the answer is 7!