Question

Calculate the mass of iodine that must be

reacted with excess phosphorus to produce

5.00 g of phosphorus(III) iodide according to

the equation below.

2P+3I2 → 2PI3

Answer 1

Solution.

$xg$ $500g$

$2P+3I_2 → 2PI_3$

$3 Mr(I_2)$ $2Mr(PI_3)$

$\dfrac{x}{3Mr(I_2)}=\dfrac{500}{2Mr(PI_3)};$

$x=\dfrac{500\sdot3Mr(I_2)}{2Mr(PI_3)};$

$x=\dfrac{500\sdot3\sdot126.9\sdot2}{2\sdot(31+126.9\sdot3)}=462g;$

Answer: $462g.$