I am hella confused with Basic Chemistry. Can anyone please help me oh my!

1. record the mass of the empty gas piston.
111.420g.
2. for each gas, record the following:
(A) name and formula Propane (C3H8) Butane (C4H10) Methane (CH4) Dioxygen (O2)
(B) Molecular weight(molar mass) (g/moles) 44.03g/mol 58.04g/mol 16.01g/mol 31.98g/mol
(C) Mass of the gas piston and 100ml gas(g) 111.603g 111.661g 111.486g 111.553g
(D) number of moles in the 100ml sample.
that's as far as I got. I need help with letter D still and the rest of my questions if anyone could help.
3. to verify Avofadro's Law, calculate the average number of moles for the four gases along with the percent deviation for each gas, according to the formula:
Þviation=(moles of gas)-(average for all gases)/(average for all gases)*100%

(A) average number of moles in 100ml for all four gases:
(B) % deviation for each gas:
(C) do your results confirm Avogadro's Law?

4. volume occupied by one mole of gas at STP. One mole of any gas at STP conditions (standard temperature and pressure) accupies 22.4 liters. See how well the average number of moles for the gases with this.

(A) calculate the volume occupied by one mole of gas from the average number of moles in the 100ml volume using the following proportionality equation:
average moles/ 100ml=1mole/ (volume of 1 mole)

(B)you should get something close to 22.4L. This number must then be corrected for non-STP conditions in the lab as follows. Click on the wall chart at the top of the lab (just under the lab title) to view the current temperature and pressure in the room. For ideal gases, PV/T is constant, and at STP, P=1atm, V=22.4L, T=273.15K (0C). Solve for the corrected volume at the lab temperature (20degrees celsius) and pressure. Recalculate the expected moles in the corrected volume at lab temperature and pressure. Report your experimental results using the corrected volume for 1 mole of gas, along with the percent deviation.

(C) Explain ehat might have caused your value to differ from the accepted value.

1.] 111.420g
2.]

a) b) c) grams d) g/mol e) mol
----------------------- ---------------- ----------- -------------- -----------
- C3H8 Propane - 111.603g 0.183 44.10 MW 0.0041
- C4H10 Butane - 111.661g 0.241 58.12 MW 0.0041
- CH4 Methane - 111.486g 0.066 16.04 MW 0.0041
- N2 Nitrogen - 111.536g 0.116 28.01 MW 0.0041
- O2 Oxygen Gas- 111.553g 0.133 32.00 MW 0.0041


3.] 0.0041-0.0041/0.0041X100
a)0.0041
b)2.44%
c)Yes, it confirms Avogadro's Law


4.]

a)x/0.10=1/22.4
x= 0.0044

b) PV/T= n*R
0.10/294*0.082=n
n= 0.0041 mol
c) We were calculating at a different temperature so the standards were not accomplished, and this is what caused the value to differ from the accepted value.