Explanation:
Balanced Equation
P
2
O
3
+
3H
2
O
→
2H
3
PO
3
First use the balanced equation to determine the mole ratio between
H
3
PO
3
and
P
2
O
3
. This ratio will be used to determine the moles
P
2
O
3
required to produce
10.2
moles
H
3
PO
3
.
Mole Ratio Between
P
2
O
3
and
H
3
PO
3
from the balanced equation.
1
mol P
2
O
3
2
mol H
3
PO
3
and
2
mol H
3
PO
3
1
mol P
2
O
3
Multiply the moles
H
3
PO
3
by the molar mass that cancels
H
3
PO
3
and leaves
P
2
O
3
10.2
mol H
3
PO
3
×
1
mol P
2
O
3
2
mol H
3
PO
3
=
5.10 mol P
2
O
3
Now that the moles
P
2
O
3
required to produce
10.2 mol H
3
PO
3
are known, multiply the number of moles by its molar mass,
109.945 g/mol
. https://www.ncbi.nlm.nih.gov/pccompound?term=P2O3 This will give the mass in grams needed for
P
2
O
3
to produce
10.2 mol H
3
PO
3
.
5.10
mol P
2
O
3
×
109.945
g P
2
O
3
1
mol P
2
O
3
=
561 g P
2
O
3
rounded to three significant figures
