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cpt_azad
05-25-2005, 07:00 AM
oh god oh god oh god...need help !!11

Determine the volume of .200M NaOH required to completely neutralize 250.0mL of 0.220M H3PO4.

i need the steps on how to do this (above)

oh god


Determine the new concentration after these dilutions:

a) 150mL of .450M HCl to 4.50L

b) 40.0mL of 1.8M NaOH to 800.0mL



Calculate the concentration of each ion after mixing these solutions wher NO REACTION occurs:

a) 2.0L of 0.60M Copper (II) Nitrate and 2.0L of 0.20M Iron (III) Nitrate

b) 400.0mL of 0.200M Aluminum Chloride and 200.0mL of 0.300M Sodium Chloride

please guys, you're my last hope, i have no idea how to do this and it's due tomorrow. i forgot my binder at school and all my notes are in there, i looked on google but i can't find a good example(s) of it or steps on how to do it. PLEASE HELP ME!!!!

S!X
05-25-2005, 07:28 AM
Damn meng, Im pretty sure none of these mofos in the lounge know wtf this stuff is.

cpt_azad
05-25-2005, 07:31 AM
i think i figured out number 1, not sure, could someone confirm on it?:

Equation (please lemme know if its balanced properly!):

H3PO4 + 3NaOH --> 3H2O + Na3PO4

n=CV --> 0.250L(0.200M H3PO4) = 0.0550 moles H3PO4
NaOH:H3PO4 --> 3:1 --> 3(0.0550moles H3PO4) = 0.165 moles NaOH
0.165mole NaOH/0.200M --> 0.825L of NaOH is required to completely neutralize the H3PO4.

Mr. Mulder
05-25-2005, 07:40 AM
yeah......yeah that looks pretty good to me :ermm:

MCHeshPants420
05-25-2005, 07:41 AM
Looks completely wrong to me, unfortunately I'm off to my interview now. Maybe laters.

cpt_azad
05-25-2005, 07:47 AM
damnit mchesh :angry: now ur making me even more worried ahhhhhhhhh

99%
05-25-2005, 08:12 AM
Damn meng, Im pretty sure none of these mofos in the lounge know wtf this stuff is.

:cry:

cpt_azad
05-25-2005, 08:24 AM
well he is rite, when was the last time anyone in the lounge actually helped someone instead of spamming the fuck out of a thread? maybe i posted this in the wrong place....

Guillaume
05-25-2005, 08:50 AM
Yeah, maybe we need a "I-need-someone-else-to-do-my-homework-world". :dry:

99%
05-25-2005, 08:59 AM
Yeah, maybe we need a "I-need-someone-else-to-do-my-homework-world". :dry:

I think its great when people ask for solutions to homework whether its essays/maths whatever - reminds me to get of things i once knew - if i know the answer ill say so
they generally add different topics to the board instead of usual sftwr/hrdwr/fileshr/igottagreatlink/myanusitches threads.

I never did physics nor chemistry in school - pity - tons of usefull info there for the later life.

manker
05-25-2005, 09:05 AM
well he is rite, when was the last time anyone in the lounge actually helped someone instead of spamming the fuck out of a thread? maybe i posted this in the wrong place....I think you did post this in the wrong place. Most folk I talk to think you're an arse.

Have you thought about starting afresh under a new handle and not being such a prick. I mean, who are you to condescend to a group of people and for you, of all people, to berate them for spamming in the same sentence is pushing the realms of credibility a bit, dontcha think.

MCHeshPants420
05-25-2005, 09:12 AM
Yeah, maybe we need a "I-need-someone-else-to-do-my-homework-world". :dry:

I think its great when people ask for solutions to homework whether its essays/maths whatever - reminds me to get of things i once knew - if i know the answer ill say so
they generally add different topics to the board instead of usual sftwr/hrdwr/fileshr/igottagreatlink/myanusitches threads.

I never did physics nor chemistry in school - pity - tons of usefull info there for the later life.


Yeah, but it's more fun to take the piss and wind them up with the wrong answers. The best thing you can say to them is to manage their time better and do their homework when they get it or at the very least start it.

Snee
05-25-2005, 11:26 AM
well he is rite, when was the last time anyone in the lounge actually helped someone instead of spamming the fuck out of a thread? maybe i posted this in the wrong place....
:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: *




*at you, not with you.

JPaul
05-25-2005, 11:41 AM
A pattern is emerging.

A h4r5h pattern, but a pattern none the less.

DanB
05-25-2005, 04:43 PM
well he is rite, when was the last time anyone in the lounge actually helped someone instead of spamming the fuck out of a thread? maybe i posted this in the wrong place....


Says the spamming cawksucker himself :dry:

Mr JP Fugley
05-25-2005, 05:03 PM
well he is rite, when was the last time anyone in the lounge actually helped someone instead of spamming the fuck out of a thread? maybe i posted this in the wrong place....


Says the spamming cawksucker himself :dry:
Shhh, she'll snap you like a dry twig.

Mr JP Fugley
05-25-2005, 05:06 PM
Sorry wrong forum

enoughfakefiles
05-25-2005, 05:52 PM
The answer is spam. :D

Gripper
05-25-2005, 08:58 PM
LSD=Aciiid :)

No I have no idea about your home work,so I thought I'd :spamfrown

HCT
05-25-2005, 10:20 PM
Dilutions

When given a solution, you can diluted by adding more of the solvent. to calculate how much solvent to add, use the formula: M1V1=M2V2, where M1 is the initial concentration and V1 is the initial volume. M2 is the concentration you want it diluted to and V2 is the volume of the new solution.


hope it helps:)

exo_body
05-25-2005, 10:51 PM
hey man, the first one you did was wrong sorry. the equation is:
NaOH + H3PO4 -> NaH2PO4 + H20
now using the details of H3PO4
conc: 0.2 0.22
vol: 250/1000
moles: =0.22*(250/1000) (therefore, as its a 1:1 reaction, theres the same number of moles of NaOH)

now to work out the volume, you use the equation volume = moles/volume

so [0.22*(250/1000)] 0.2
will give you 0.275dm^-3, then just multiply by 1000 to get the answer in cm^-3

hope thats any help, i think its right. do you want the others done? they follow the same kinda pattern, but they seem slightly easier. well question 2 does.

cpt_azad
05-25-2005, 10:51 PM
fuck you all, especially manker :D

exo_body
05-25-2005, 11:02 PM
the answer to the next question (with the part a) and b) ) is:

a : 0.015 M
b: 0.09 M

again, these are the answers im getting just. if you want the working out just ask.

JPaul
05-25-2005, 11:21 PM
fuck you all, especially manker :D
Break his arm with a punch captain asda.

It's the only sensible coarse.

manker
05-26-2005, 12:50 PM
fuck you all, especially manker :DEven the ones who tried to help.

See, this is why my arse evaluation wasn't contradicted.

JPaul
05-26-2005, 04:13 PM
fuck you all, especially manker :DEven the ones who tried to help.

Even the wrong ones :blink:

manker
05-26-2005, 04:33 PM
Even the ones who tried to help.

Even the wrong ones :blink:
:unsure:

loadedet
05-26-2005, 08:43 PM
All i would do would pour measured amounts of a neutraliser to the solution, then test the pH with a universal indicator then rite down the amount that was used on a table 4 even more quantafiable results use a colouromiter

enoughfakefiles
05-26-2005, 08:53 PM
All i would do would pour measured amounts of a neutraliser to the solution, then test the pH with a universal indicator then rite down the amount that was used on a table 4 even more quantafiable results use a colouromiter

Are you not better off just usinig a continuum tramfunctioner. :unsure:

cpt_azad
05-27-2005, 06:57 AM
hey man, the first one you did was wrong sorry. the equation is:
NaOH + H3PO4 -> NaH2PO4 + H20
now using the details of H3PO4
conc: 0.2 0.22
vol: 250/1000
moles: =0.22*(250/1000) (therefore, as its a 1:1 reaction, theres the same number of moles of NaOH)

now to work out the volume, you use the equation volume = moles/volume

so [0.22*(250/1000)] 0.2
will give you 0.275dm^-3, then just multiply by 1000 to get the answer in cm^-3

hope thats any help, i think its right. do you want the others done? they follow the same kinda pattern, but they seem slightly easier. well question 2 does.

thanks dude, i took my test today and i figured it out, i didnt' realize someone actually posted the answer, once again thanks for taking the time to help a guy out i owe you one. at least theres some good ppl in this forum.

@manker, jesus man just STFU will ya?

MCHeshPants420
05-27-2005, 08:20 AM
hey man, the first one you did was wrong sorry. the equation is:
NaOH + H3PO4 -> NaH2PO4 + H20
now using the details of H3PO4
conc: 0.2 0.22
vol: 250/1000
moles: =0.22*(250/1000) (therefore, as its a 1:1 reaction, theres the same number of moles of NaOH)

now to work out the volume, you use the equation volume = moles/volume

so [0.22*(250/1000)] 0.2
will give you 0.275dm^-3, then just multiply by 1000 to get the answer in cm^-3

hope thats any help, i think its right. do you want the others done? they follow the same kinda pattern, but they seem slightly easier. well question 2 does.

I did chemistry at school so I can say this with confidence (although I'll admit I totally failed), those answers are right.