A20-l flask contains a mixture of nitrogen gas and oxygen gas at 25 °c.
the total pressure of the gaseous mixture is 0.91 atm, and the mixture is
own to contain 0.050 mol n2. calculate the partial pressure of oxygen
and the moles of oxygen present.

12*2*6.022*10^23. Atoms of hydrogen.

Explanation:

First of all if u know that 1 molecule of calcium hydroxide contain 2 hydrogen atom and 1 mole of calcium hydroxide contain 6.022*10^23 molecules of calcium hydroxide.

Hence 1 mole of calcium hydroxide contain 2*6.022*10^23 atom of hydrogen.

So 12 mole of calcium hydroxide contain =12*2*6.022*10^23. Atoms of hydrogen.