April 13, 2021, 04:26:56 AM
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### Topic: mixture  (Read 1032 times)

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#### Borek

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##### Re: mixture
« Reply #15 on: March 25, 2021, 05:44:23 PM »
ok i calculated that the mass of the mixture is 0.857g

That was given, so you have not calculated it - but perhaps you expressed this information using an equation. Hard to say not seeing your work.

Quote
but how to set up the system and what is the volume of air used for

Volume and mass are required to express the density.

can I solve without the system in some way

No.

Quote
and how to use the data of 4.52 air volume. does that mean 4.52 * 0.21 for each equation

4.52*0.21 is the volume of oxygen required to burn all gases.

Assuming you have n liters of CH4, what is the volume of oxygen required to burn it?
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#### Orcio_Dojek

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##### Re: mixture
« Reply #16 on: March 25, 2021, 05:44:41 PM »
@inorganiic

1. Calculate density of CH4, H2 and CO at normal conditions (T = 20 C, p = 1 atm).
2. If mixture composes of 100 % CH4 it will have density you have calculated. If 100 % H2 - some other density. If 100 % CO - yet another density.
3. Calculate how many litres of air is needed to burn 1 litre of pure CH4, 1 litre of pure H2, and 1 litre of pure CO.
4. You know that mixture contains only CH4, H2 and CO.
5. Points 2, 3 and 4 gives you system of equations (3 equations with 3 variables) to solve.

#### inorganiic

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##### Re: mixture
« Reply #17 on: March 25, 2021, 06:15:05 PM »
@Orcio_Dojek
I still can't solve it, I can't do the system, I calculated the densities 1.1515, 0.3290, 0.1645 and how much it takes to burn 1 dm3, 0,526 for CO and H2 and 2,107 but it doesn't work. Can you solve it I need for the entrance test. Solution is 20 percent for H2, 30 percent for CH4 and 50 percent for CO

#### Orcio_Dojek

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##### Re: mixture
« Reply #18 on: March 26, 2021, 06:20:49 PM »
Quote
I calculated the densities 1.1515, 0.3290, 0.1645

What the hell? These numbers can't be correct.

Also:
Quote
how much air it takes to burn 1 dm3, 0,526 for CO and H2 and 2,107 for CH4

I wonder how it is possible if mixture cointains only CH4, H2 and CO, and for one liter it is required 4,52 liters of air
« Last Edit: March 26, 2021, 07:08:33 PM by Orcio_Dojek »

#### inorganiic

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##### Re: mixture
« Reply #19 on: March 27, 2021, 03:33:55 PM »
Can you solve it  because i can not almoast three days

#### Orcio_Dojek

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##### Re: mixture
« Reply #20 on: March 27, 2021, 04:05:22 PM »
1. Density of CH4, CO, H2 and density of their mixture.
2. How much air is needed to burn 1 liter of CH4, CO, H2 and their mixture.
3. Mixture cointains only CH4, CO and H2.

Rest is only calculation.

#### inorganiic

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##### Re: mixture
« Reply #21 on: March 27, 2021, 05:07:25 PM »
But that is a problem i can not get 20 30 and 50 percent

#### Orcio_Dojek

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##### Re: mixture
« Reply #22 on: March 27, 2021, 05:15:04 PM »
I know. Concentration of H2 is lower than given answer.

Maybe author mistaken "normal" with "standard" (T = 273 K) conditions, I don't know.

#### inorganiic

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##### Re: mixture
« Reply #23 on: March 27, 2021, 06:15:08 PM »
Can you text this here how you got the answer, i would be so thankful

#### Orcio_Dojek

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##### Re: mixture
« Reply #24 on: March 27, 2021, 06:43:04 PM »
@inorganiic

I must see your calculations before that.

#### inorganiic

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##### Re: mixture
« Reply #25 on: March 27, 2021, 06:53:29 PM »
In normal conditions we need 2,38l of air for H2 and CO from proportion, also when i made proportion i get 0,5l of O2 then for CH4 2l of O2 and 9,521l of air and then all is complicated and i can not get the right solution

#### Orcio_Dojek

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##### Re: mixture
« Reply #26 on: March 28, 2021, 04:43:47 AM »
I know. My results (concentration of H2) also differ slightly from that given by the author.

#### inorganiic

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##### Re: mixture
« Reply #27 on: March 28, 2021, 05:01:07 AM »
Can you write me how you got your results detailed

#### inorganiic

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##### Re: mixture
« Reply #28 on: March 28, 2021, 05:05:32 AM »
Or better photo them if you can

#### Borek

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##### Re: mixture
« Reply #29 on: March 28, 2021, 10:39:54 AM »
Can you write me how you got your results detailed

Or better photo them if you can

Per the forum rules you agreed to when registering we don't give solutions. Begging and pestering won't change that.

However, if you post how you approached the problem (and you were given multiple hints) we will gladly help you solve the problem.
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