Sound: missed test questions

In summary, the ideal gas law equation PV=nRT is used to solve for various properties of gases. In the first question, a sample of Co2 with a known number of molecules at STP can be converted to volume using the ideal gas law. In the second question, the mass of H in a container can be determined using the ideal gas law with known volume, pressure, and temperature. In the third question, the ideal gas law can be used to solve for the necessary gauge pressure to achieve a desired density. And in the final question, the number of gas molecules in a container can be calculated using the ideal gas law with known volume, pressure, and temperature. By understanding and using this equation, we can solve for various
  • #1
Dx
1) A sample of Co2 contains 3.01x10^23 molecules at STP. what volume does this sample occupy?
I have the multiple choice answers but need help explaining why you chose that answer.

11.2L
44.8L
32.7L


2) a 25L container hold H gas at gauge pressure 1.25atm and temo 0 degrees celcius. what's mass of H in this container

2.8g
4.2g
5.6g

3) An ideal gas has density of 1.75kg/m^3 at gauge pressure 160kPa. what must be the gauge pressure isf density of 1 kg/m^3 is desired at the same temp?

356kPA
280kPA
48KPa

4) an ideal gas in container of volume 100cm^3 at 20 degrees C has pressure of 100N/m^2. determine the number of gas molecules in the container

6x10^23
2.5x10^18
5.2x10^18

I am not going to put my work here since I've already missed them. I can't go on not understanding why or what these answers were. I have gone back to re-read the chapter on this and still unclear with the ideal gas law, i know its said to be simple but its not clicking here. I don't need a long explanation just the answer you got and briefly how you derived it. If you feel you don't have to answer this cause it vilates so rules its like i said "Its not homework but missed test questions that for my own personnel conquest I must try to solve but need your help, please" Please understand I hold each of you in the highest respect and thank you for all youve done. Its really been a great help for me to better understand this subject.
I applaude you all!
Dx :wink:
 
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  • #2
You use the same equation for all of these: PV=nRT

P=absolute pressure
V=volume
n=# of moles
R=ideal gas constant
T=temp (in oK)
 
  • #3
Hey, check this out:

http://www-tech.mit.edu/Chemicool/idealgas.html [Broken]

Neato.
 
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1. What is sound?

Sound is a form of energy that is produced by vibrations and travels through a medium, such as air, water, or solids, in the form of waves.

2. How do we hear sound?

Sound waves enter our ears and cause our eardrums to vibrate. These vibrations are then transmitted to the inner ear, where they are converted into electrical signals and sent to the brain, allowing us to perceive sound.

3. What factors affect the speed of sound?

The speed of sound is affected by three main factors: the medium it travels through, the temperature of the medium, and the density of the medium. Generally, sound travels faster in denser, warmer mediums.

4. What is the difference between pitch and volume?

Pitch is a measure of the frequency of a sound wave, or how fast the waves are vibrating. A higher frequency produces a higher pitch, while a lower frequency produces a lower pitch. Volume, on the other hand, is a measure of the amplitude of the sound wave, or the height of the waves. A higher amplitude produces a louder sound, while a lower amplitude produces a softer sound.

5. How does sound travel through different mediums?

Sound travels through different mediums by causing the molecules of the medium to vibrate and transmit the sound energy. In solids, the molecules are tightly packed, allowing sound to travel quickly. In liquids, the molecules are more spread out, so sound travels slower. In gases, the molecules are even more spread out, resulting in slower sound travel compared to solids and liquids.

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