Question

How many grams of lithium are in 0.356 moles of lithium phosphide? 

Answer 1

Molecular Formula, $Li_3P$

1 mole of lithium phosphide contains = 3 moles of lithium

0.356 moles of lithium phosphide contains = 1.068 moles of lithium

Mass of lithium = $7\times1.068=7.476\space g$