A student weighed 1.10 g of lithium chloride to use in a reaction. How many moles is this?

$\text{Approx 0.025 mol}$.
$\text{Moles"= "Mass"/"Molar mass}$ $=$ $\frac{1.10 \cdot g}{42.39 \cdot g \cdot m o {l}^{-} 1} \cong 0.025 \cdot \text{mol}$.