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Need some help with chemistry equations

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If I have 5 moles of P4O6 (approx 1099.45 grams), what is the weight (in grams) of phosphorus in this compound? Please explain because I'm very confused.

Oct 6, 2018
edited by Cent0rea88  Oct 6, 2018

#1
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Convert from moles into grams:
5 mol of P4O6 (tetraphosphorus(III) hexoxide)

Split the chemical formula P4O6 into a tally of its elements:
atom | tally
O |       6
P |       4

Using the atomic masses of the elements O (15.999 u) and P (30.973761998 u), calculate the total mass of each element in 1 molecule of P4O6:
atom | tally | atomic mass | mass in molecule
O |        6 |     15.999 u |              95.994 u
P |         4 |     30.973761998 u | 123.89504799 u

Calculate the molecular mass of P4O6 by adding the mass of each type of atom:
95.994 u + 123.89504799 u = 219.89 u

Since 1 u corresponds to 1 g/mol, the molar mass of P4O6 equals 219.89 g/mol. The number of grams equals the molar mass of P4O6 multiplied by the molar amount:

(5 mol) * 95.994 =479.97 grams of Oxygen + (5 mol)* (123.895 g/mol) =619.475 grams of Phosphorus =1,099.45 grams in 5 moles of P4O6

Oct 6, 2018
edited by Guest  Oct 6, 2018
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P = 30 . 97696         x 4 = 123.9078

O=15.9994               x 6 =95.9964

123.9078 / (123.9078 +95.9964)    * 1099.45  = 619.498 gm of P

Oct 7, 2018