Answer:
4.525% is the percentage by volume of oxygen in the gas mixture.
Explanation:
Total pressure of the mixture = p = 4.42 atm
Partial pressure of the oxygen = 
Partial pressure of the helium = 
(Dalton law of partial pressure)
According Avogadro law:
(At temperature and pressure)
Volume occupied by oxygen gas =
Total moles of gases = n = 1 mol
Total Volume of the gases = V
Percent by volume of oxygen in the gas mixture:
<span>(0.038 / 100) * 763 = 0.29 mmHg
hope it helps
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To know the number of atoms, it will be necessary to use the formula of avogadro. We calculate the number of moles then we can calculate the number of avogadro.
The molar mass of:
Phosphorus = 31g / mol
Mercury = 200 g / mol
Bismuth = 209 g / mol
Strontium = 87 g / mol.
The number of avogadro (N) is 6.023 10 ^ 23
n = m (mass) / M (molar mass)
number of atoms = n. N = m / M . N
number of phosphorus atoms = 5.14/31 . 6.023 10^23 = 9.98 10 ^ 22 atoms
Number of atoms of mercury = 2.16/200 . 6.023 10^23 = 6.5 10 ^ 21 atoms
Number of bismuth atoms = 1.8/209 . 6.023 10^23 = 5.18 10 ^ 21 atoms
Number of strontium atoms = 8.8 x 10-2 /87 . 6.023 10^23 = 6.09 10 ^ 20 atoms
