Question
$$1.6\,g$$ of an organic compound gave $$2.6\,g$$ of magnesium pyrophosphate. The percentage of phosphorus in the compound is
A.
$$45.38\% $$
B.
$$54.38\% $$
C.
$$37.76\% $$
D.
$$19.02\% $$
Answer :
$$45.38\% $$
Solution :
$$\eqalign{
& \% \,\,{\text{of}}\,\,P = \frac{{62}}{{222}} \times \frac{x}{w} \times 100 \cr
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \frac{{62}}{{222}} \times \frac{{2.6}}{{1.6}} \times 100 \cr
& \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 45.38\% \cr} $$