June 18, 2021, 10:50:36 PM
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### Topic: Help with calculating volume of gas collected over water  (Read 175 times)

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#### JeffLindla123

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##### Help with calculating volume of gas collected over water
« on: June 07, 2021, 02:56:42 PM »
4.52 L of fluoride gas is combined with 25.3 g of Hm metal (Hm being a made up element with a molar mass of 49.11 g/mol). The resulting compound HmF2. What is the volume of dry HmF2 gas is collected over water at 26 degrees Celsius and 104.24 kPa

« Last Edit: June 07, 2021, 04:11:31 PM by JeffLindla123 »

#### Borek

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##### Re: Help with calculating volume of gas collected over water
« Reply #1 on: June 07, 2021, 03:22:34 PM »
There is definitely some typo in your post and some missing information that makes it impossible to solve/help

HmF2 + Hm produces some gas and we are expected to find the amount of the HmF2 produced?

Is it intended to be

Hm + F2  HmF2(g)

?

Even if so, we are not given any information to base the stoichiometry calculation on.
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#### JeffLindla123

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##### Re: Help with calculating volume of gas collected over water
« Reply #2 on: June 07, 2021, 03:34:55 PM »
There is definitely some typo in your post and some missing information that makes it impossible to solve/help

HmF2 + Hm produces some gas and we are expected to find the amount of the HmF2 produced?

Is it intended to be

Hm + F2  HmF2(g)

?

Even if so, we are not given any information to base the stoichiometry calculation on.

I've changed the original question to have all the information. Sorry

#### mjc123

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##### Re: Help with calculating volume of gas collected over water
« Reply #3 on: June 07, 2021, 03:49:37 PM »
Please don't change your original post once it's been replied to; it makes the reply meaningless. You can make corrections in a subsequent post if necessary.

#### Borek

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##### Re: Help with calculating volume of gas collected over water
« Reply #4 on: June 07, 2021, 03:49:56 PM »
So it is a limiting reagent problem, isn't it?

There is a slight problem with fluorine, volume is given but not conditions, so it is not clear how to convert volume to moles. Assume whatever STP you want, just state it clearly in your solution.
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#### JeffLindla123

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##### Re: Help with calculating volume of gas collected over water
« Reply #5 on: June 07, 2021, 04:12:43 PM »
So it is a limiting reagent problem, isn't it?

There is a slight problem with fluorine, volume is given but not conditions, so it is not clear how to convert volume to moles. Assume whatever STP you want, just state it clearly in your solution.

fluorine is held at STP and after getting 4.52 L of HmF2 using stoichiometry. I need to determine how much of it is actual dry gas.

#### Borek

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##### Re: Help with calculating volume of gas collected over water
« Reply #6 on: June 08, 2021, 03:06:11 AM »
fluorine is held at STP

Even that is a bit ambiguous, but OK.

Quote
and after getting 4.52 L of HmF2 using stoichiometry

That would be at STP (assuming STP to be exactly the same for both gases), but you are actually given temperature and pressure which clearly are not STP. Have you calculated the volume of the gas as it was collected?

Quote
I need to determine how much of it is actual dry gas.

Do you understand the difference between dry gas and wet gas?
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