Sciencemadness Discussion Board

percentage of NH4ClO4 in a reaction

ionic bond - 10-8-2004 at 02:17

Hi

given the reaction:

2NH4ClO4 ---> N2 + Cl2 + 2O2 + 4H2O

45.6 gr of impure sample of NH4ClO4 is placed in a 5.0 L flask and heated to 250 C. If the pressure of H2O resulted is 2750 mmHg. What is the precentage of NH4ClO4 in the sample?

Thanks

vulture - 10-8-2004 at 07:27

We're not going to answer this question for you. Try putting some effort into it yourself, then come back and report.

Members, please don't spoonfeed him the answers.

Dodoman - 10-8-2004 at 07:50

How old are you? You should be ashamed. In my country that's like highschool physics. I don't know about you but i guss that's highschool physics too.

JohnWW - 10-8-2004 at 14:28

Doing that to 46 gm of NH4ClO4 would result in the flask blowing up! Anyone standing near it would also stand a good chance of being "taken out".

John W.

ionic bond - 11-8-2004 at 05:20

I am 17 years old

vulture - 11-8-2004 at 05:51

That's not an excuse.

Like I said before, describe or provide some figures how you started calculating and where you failed.

ionic bond - 15-8-2004 at 16:12

I tried to calculate the number of moles of water

PV = nRT

but I don't have the V here!

BromicAcid - 15-8-2004 at 16:21

It's a 5.0 L flask.......

NH4ClO4

MadHatter - 15-8-2004 at 16:46

I might try to dry out NH4ClO4 with a flask submerged in boiling
water with CaCl2 in a drying tube. But to do this over an open flame,
you're asking for a detonation. Like Vulture suggested, do some research
or UTFSE ! Otherwise, just buy it !

BromicAcid - 15-8-2004 at 17:09

I'm pretty sure this was just a homework question, not a general purity assay.

ionic bond - 16-8-2004 at 11:22

thats right

its just a question

but not a homework because we don't have school these days

I will try:

PV = nRT

n = PV/RT

n = 3.62*5/0.0821*523 = 0.422 moles of NH4ClO4

Mw = 117.5

117.5*0.211= 24.8

24.8 / 45.6 = 54%

???

vulture - 16-8-2004 at 12:30

No, 0.422 moles of water vapor...

ionic bond - 16-8-2004 at 15:35

that was a mistake

0.211 was the number of moles of NH4ClO4

vulture - 17-8-2004 at 07:05

Ah yes, I noticed now, I was wondering where the 0.211 came from.

Anyways, it should be correct now.

Ofcourse, this isn't very realistic, water vapor doesn't behave as an ideal gas at pressures of several atmospheres.

[Edited on 17-8-2004 by vulture]

ionic bond - 17-8-2004 at 07:24

thanks alot

:)