Question

You need 150g of pure lithium for an experiment you're doing. You have 675g of lithium oxide (Li2O). Can you extract all the lithium you need from the amount of compound you have? Show your reasoning.

Answer 1

Answer: Yes we can extract all the lithium from the amount of compound we have.

Explanation:

To calculate the moles :

$moles=\frac{\text {given mass}}{\text {Molar mass}}$

$\text{Moles of} Li=\frac{150g}{7g/mol}=21.4moles$

$\text{Moles of} Li_2O=\frac{675g}{30g/mol}=22.5moles$

$2Li_2O\rightarrow 4Li+O_2$

According to stoichiometry :

2 moles of $Li_2O$ produce 4 moles of $Li$

Thus 22.5 moles of $Li_2O$ will produce=$\frac{4}{2}\times 22.5=45moles$  of Li

As 21.4 moles is a lesser quantity than 45 moles, thus it can be produced