What part of chemistry is this
Number of moles of CO2 =
Mass /Ar
= 50.2 / (12 + 32)
1.14 mols
For every 1 mol of gas, there will be
24000 cm^3 of gas
Vol. = 1.14 x 24 dm^3
= 27.36 dm^3
This problem is very easy to answer. You simply have to look at the subscripts of each element of the compound.
1. For caffeine, which has a molecular formula of C₈H₁₀N₄O₂, it contains 8 atoms of Carbon, 10 atoms of Hydrogen, 4 atoms of Nitrogen and 2 atoms of Oxygen.
2. For Iron(III) Sulfate, which has a molecular formula of Fe₂(SO₄)₃, it contains 2 atoms of Iron, 3 atoms of Sulfur, and 12 atoms of Oxygen.
First of all, as you seen the gases are noble which means that will not react with each other and in this case each gas create individual pressure.
P= total pressure
P = pressure of neon
P = pressure of argon
P = pressure of helium {which is required}
P = P + P + P
1.25 = 0.68 + 0.35 + P
P = 1.25 - [0.68 + 0.35] = 0.22 atm