Question

What is the molarity of a 21.2 g of LiCI of a 4. 0 L solution?

Answer 1

Molarity is defined as the moles of a substance in a volume of solution. That is, we can represent it with the following equation:

`\text{Molarity}=\frac{\text{Moles of solute}}{L\text{ of solution}}`

We are given the liters of the 4.0L solution. We must find the moles of LiCl that represent 21.2g of LiCl. To do this conversion we use the molar mass of LiCl equal to 42.394g/mol. Therefore, the moles of LiCl will be:

`\begin{gathered} \text{molLiCl}=GivengLiCl*(1molLiCl)/(MolarMass,gLiCl) \\ \text{molLiCl}=21.2gLiCl*(1molLiCl)/(42.394gLiCl)=0.50molLiCl \end{gathered}`

If we replace the value obtained in the first equation we will get tho molarity of the solution:

`\text{Molarity}=\frac{0.50\text{molLiCl}}{4.0L\text{ solution}}=0.13M`

The molarity of the solution will be 0.13M