## Density Lab B

bobthebuilderman
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### Re: Density Lab B

Anywho, i'll try to revive this:

1. A sample of Hydrogen has is in a 5-liter tank with a pressure of 296 torrs. There is another sample of Hydrogen gas that's in a 8-liter tank with a pressure of 530 torrs. What will the pressure be if these two samples are combined into one 13 liter tank? Answer in atms.

2. A sample of N2 gas is collected over water at 20 degrees C and a pressure of 1 atm. The volume is 250 L. What mass of N2 is collected?
3. A 500 ml sample of gas is collected at 20 degrees C and 620 mmHg. What is the volume at STP?

thanks,
~ bob ~
yes

ILikeBirds
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### Re: Density Lab B

Anywho, i'll try to revive this:5

1. A sample of Hydrogen has is in a 5-liter tank with a pressure of 296 torrs. There is another sample of Hydrogen gas that's in a 8-liter tank with a pressure of 530 torrs. What will the pressure be if these two samples are combined into one 13 liter tank? Answer in atms.

2. A sample of N2 gas is collected over water at 20 degrees C and a pressure of 1 atm. The volume is 250 L. What mass of N2 is collected?
3. A 500 ml sample of gas is collected at 20 degrees C and 620 mmHg. What is the volume at STP?

thanks,
~ bob ~

Let's see here.....

1: The way I would do this might be little weird, but I first multiply 5 by 296 and 8 by 530. Then add (5*296) 1480 and (8*530) 4240 to get 5720, then divide by 13 to get 440. Conversion from torr to atm is to divide by 760 so your answer would be 440/760 or .5789 atm. I think.

2: So first you wanna use the Ideal Gas law to solve for n or number of moles, which I got as 10.3928 using the gas constant of .082057 K atm mol L, and once you have moles you use molar mass, or grams per mole, to find mass. N2's molar mass is 28.0134 which you can find using the atomic weight of Nitrogen, ~14, and multiplying it by 2 (N2). Now that you have molar mass, multiply by moles to get grams of substance, or 28.0134 times 10.39, which is 291.139 g, and my final answer whew! that was a lot of typing. anyway, here's question 3: To start off, let's calculate the number of moles. Using the ideal gas law again, (and converting from 620 mmHg to .815789 atm because I like atm better) as well as the gas constant, we get .016956 mol, and then using STP, or 273.15 K and 1 atm, we can find that the new volume is .38 L or 380.05 mL which might be wrong but I'm pretty sure it's right.

Next question: A hot air balloon has a mass of 300 kg, and the air inside weighs 17000 N. Determine the maximum load the balloon can handle if it displaces 25000 N of air.

Also is anyone else excited for Ornithology next year?!?!
Kealing MS:
Y'all underestimate us Texans.

Fallsbury
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### Re: Density Lab B

ILikeBirds wrote: Next question: A hot air balloon has a mass of 300 kg, and the air inside weighs 17000 N. Determine the maximum load the balloon can handle if it displaces 25000 N of air.
[/quote]
I'm pretty sure this is wrong but: 225060 N or around 516 kg. Honestly, I'm not excited for Ornithology next year, I'm already sick of ID events.
Last edited by Fallsbury on May 19th, 2019, 10:58 am, edited 1 time in total.
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Fallsbury
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### Re: Density Lab B

I just edited my last post.
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Fallsbury
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### Re: Density Lab B

Well dunno if that's right but next here is the next question:

What is the concentration of uranium in ppm if 18 milligrams of uranium are found in 40 kg of soil?
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