Answer : The number of moles of oxygen needed are, 1.5 moles.
Explanation :
The balanced chemical reaction will be:

Now we have to calculate the moles of oxygen.
From the balanced chemical reaction we conclude that,
As, 6 moles of water vapor produces from 5 moles of oxygen
So, 1.80 moles of water vapor produces from
moles of oxygen
Therefore, the number of moles of oxygen needed are, 1.5 moles.
Answer:
V = 11.21 L
Explanation:
Given data:
Volume of helium = ?
Number of moles = 0.500 mol
Temperature = 273.15 K
Pressure of gas = 1 atm
Solution:
Formula:
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
V = nRT/P
V = 0.500 mol × 0.0821 atm.L/ mol.K × 273.15 K / 1 atm
V = 11.21 L / 1
V = 11.21 L
In the modern periodic table when elements are arranged according to their atomic number.