Answer
a. $4.5*10^{-3} \text{ mol $P_4O_6$}$
b. $3.2*10^{-3}\text{ mol $Ca_3(PO_4)_2$}$
c. $7.0*10^{-3}\text{ mol $Na_2HPO_4$}$
Work Step by Step
a.
$1.00 \text{ grams $P_4O_6$}*\frac{1 \text{ mol $P_4O_6$}}{219.89 \text{ grams $P_4O_6$}}=4.5*10^{-3} \text{ mol $P_4O_6$}$
b.
$1.00 \text{ grams $Ca_3(PO_4)_2$}*\frac{1 \text{ mol $Ca_3(PO_4)_2$}}{310.17 \text{ grams $Ca_3(PO_4)_2$}}=3.2*10^{-3}\text{ mol $Ca_3(PO_4)_2$}$
c.
$1.00 \text{ grams $Na_2HPO_4$}*\frac{1 \text{ mol $Na_2HPO_4$}}{141.96 \text{ grams $Na_2HPO_4$}}=7.0*10^{-3}\text{ mol $Na_2HPO_4$}$
