Answer : The number of moles of phosphorous are 194 moles.
Explanation : Given,
Moles of [tex]P_4O_{10}[/tex] = 48.5 moles
By the stoichiometry in [tex]P_4O_{10}[/tex], there are 4 moles of phosphorus and 10 moles of oxygen.
As, 1 mole of [tex]P_4O_{10}[/tex] contains 4 moles of phosphorous
So, 48.5 moles of [tex]P_4O_{10}[/tex] contains [tex]48.5\times 4=194[/tex] moles of phosphorous
Therefore, the number of moles of phosphorous are 194 moles.
