# A compound is found to contain 1.32 moles of Li, 0.66 moles of Se, and 2.64 moles of O. What is the empirical formula of the compound?

$L {i}_{2} S e {O}_{4}$
$L {i}_{2} S e {O}_{4}$ is clearly ionic, and non-molecular ($S e {O}_{4}^{2 -}$ is an analogue of the sulfate ion, $S {O}_{4}^{2 -}$). Typically with these problems you are asked to provide the empirical formula, and then asked to provide the molecular formula given a molecular mass. The molecular formula is always a multiple of the empirical formula: $M F$ $=$ ${\left(E F\right)}_{n}$. Of course, the molecular formula might be the same as the empirical formula; in which case $n$ $=$ ??