Chemistry- Problems with Charles's Law, Combined gas laws, and Avogadro's Principle.?

Question

Charles's Law
1. A balloon is inflated with 6.22L of helium at a temperature of 36 degrees celsius. What is the volume of the balloon when the temperature is 22 degrees celsius.

Combined Gas Laws
2. A sample of ammonia gas occupies a volume of 1.58L at 22 degrees celsius and a pressure of 0.983 atm. What volume will the sample occupy at 1.00 atm and 0 degrees Celsius.

3. A student collects 285 mL of O2 gas at a temperature of 15 degrees celsius and a pressure of 99.3 kPa. The next days, the same sample occupies 292 mL at a temperature of 11 degrees celsius. What is the new pressure of the gas?

Avogadro's Principle
4. How many moles of acetylene(C2H2) gas occupy a volume of 3.25L at STP.

5. Determine the volume of 12.3g of formaldehyde gas(CH2O) at STP.

Answer 1

I'll do 4 and 5 since I have not learned how to do the other ones yet. We just started stiochiometry this past Monday so yea.

4) Avogadro's principle
How many moles of acetylene (C2H6) gas occupy a volume of 3.25 L at STP (standard atmosphere pressure)

You divide 3.25L and 22.4L to get rid of you L units and you'll get the moles of acetylene.

3.25/22.4
=.145 moles of acetylene @ STP

5) Determine the volume of 12.3 g of formaldehyde gas at STP.
So we have a mass and we're trying to get the volume.First we have to find the moles of formaldehyde.it's a two step equation here.

first divide 12.3g by 30.02 g
^the 30.02 is from the molar mass of CH20:
C-12.011
H2-2.01588
O-15.9994
total of 30.02
so you divide the mass 12.3 you were given with the molar mass of the compound and you get .41 moles CH2O.

Now that we have moles, we can solve to get our volume.We multiply .41 and 22.4 to get our volume

=9.184 L CH2O @ STP

Hope I helped (:

Answer 2

1. A balloon is inflated with 6.22L of helium at a temperature of 36 degrees celsius. What is the volume of the balloon when the temperature is 22 degrees celsius.

Change 36 degrees celsius to Kelvins: 36 + 273 = 309 K (plug in for T1), 22 degrees celsius = 295 K (T2)
Use V1/T1 = V2/T2
solve for V2


Combined Gas Laws
2. A sample of ammonia gas occupies a volume of 1.58L at 22 degrees celsius and a pressure of 0.983 atm. What volume will the sample occupy at 1.00 atm and 0 degrees Celsius.
- Change the temperatures to Kelvins (by adding 273)
- Use P1*V1/T1 = P2*V2/T2
Plug in all the values and solve for V2.

... i'm too tired to do the rest. just get the information from the question, plug in all the values that you have and solve for the one that is not given (the one they are asking for). and dont forget to change temp. to kelvins.

Answer 3

I'm sorry to be rude, but do you have a question you need help with or just want someone to do your homework?

The basic equations you need are:

P1V1/T1 = P2V2/T2 for Boyle's, Charles and Guy Lussac's Laws

and PV = nRT for Avogadro's principle and ideal gas law calculations.

Just plug in what your are given and solve for the rest

Answer 4

1) 5.94 L
2) 1.44 L
3) 95.6 kPa
4) 0.14
5) 9.2 L