Question

HELP PLS i have no idea what i’m doing!

Answer 1

1. 19 moles of P

2. Grams of Phosphorous produced = 15.91 grams

Step-by-step explanation:

The balanced equation is :

`2P+3O_(2)\rightarrow 2PO_(3)`

PO3 = phosphorous trioxide

O2 = Oxygen

P = phosphorous

1. Here according to stoichiometry:

2 moles of P = 3 moles of O2 = 2 moles of PO3

Or ,

2 moles of PO3 is produced from = 2 moles of P

So, 1 mole of PO3 is produced from = 1 mole of P

19 moles of PO3 is produced from = 1 x19 = 19 moles of P

Hence , Moles of P=

`19* moles\ in\ 1mole\ of PO3`

= 19 moles of P

2. Molar mass of P = 31 grams

Or 1 mole of P = 31 grams

3 mole of P = 3 x 31 = 93 gram

(whether we write 1 mole or 31 gram , it is same thing )

Again , from stoichiometry of the balanced equation,

`2P+3O_(2)\rightarrow 2PO_(3)`

3 moles of O2 reacts with = 2 moles of P

1 mole of O2 reacts with =

`(2)/(3)` of P

0.77 moles of O2 reacts with=

`0.77* (2)/(3)` of P

Always calculate for 1 mole first, then multiply by the given number

= 0.513 moles of P

Mass of 1 mole P = 31 gram

Mass of 0.5133 mole of P = 0.5133 x 31 gram

= 15.9 grams (16 grams)