Answer:
Partial pressure of H₂ is 0.375 atm
Explanation:
We apply the mole fraction to solve this.
Standard pressure is 1 atm
Mole fraction of a gas = Moles of gas / Total moles
Mole fraction of pressure = Partial pressure of gas / Total pressure
Both values are the same
Total moles = 4 moles of O₂ + 3 moles of H₂ and 1 mol of N₂ = 8 moles
3 moles H₂ / 8 moles = Partial pressure H₂ / 1 atm
(3 / 8 ) .1 = 0.375 atm → Partial pressure of H₂
The molecular formula for the compound is 
<u>Explanation</u>:
As with all of these problems, we assume 100 g of an unknown compound.
And thus, we determine the elemental composition by the given percentages.
Moles of carbon = 85.64 / 12.011
= 7.13 mol.
Moles of hydrogen = 14.36 / 1.00794
= 14.25 mol.
There are 2 moles of hydrogen per mole of carbon. And thus the empirical formula is CH
.
And molecular formula = n × (empirical formula)
Thus, 42.08 = n × (12.011 + 2 × 1.00794)
And thus n = 3, and molecular formula = 
To solve this we assume that the gas is an ideal
gas. Then, we can use the ideal gas equation which is expressed as PV = nRT. At
a constant temperature and number of moles of the gas the product of PV is
equal to some constant. At another set of condition of temperature, the
constant is still the same. Calculations are as follows:
P1V1 =P2V2
V2 = P1 x V1 / P2
<span>V2 = 153 x 4 / 203</span>
V2 = 3 L