Question #05d9c Chemistry The Mole Concept The Mole 1 Answer Michael · Ernest Z. · Stefan V. Apr 14, 2015 There are 0.75 moles. #A_r# of phosphorus = 30.97. This means that 1 mole of phosphorus atoms weighs 30.97g So 1 mole of #P_4# molecules weighs #4xx30.97= 123.88"g"# The number of moles #n# = mass/mass of 1 mole: #n=m/M_r=92.91/123.88=0.75# Answer link Related questions How do you calculate the number of moles from volume? How do you convert grams to mole? Question #258e5 Question #8d48c Why is the mole an important unit to chemists? What's the mole number? How does the mole relate to carbon 12? How does the mole relate to molecules and ions? How do you calculate the moles of a substance? How can I calculate the moles of a solute? See all questions in The Mole Impact of this question 2077 views around the world You can reuse this answer Creative Commons License