Question

Calculate the molarity of 27 grams of FeCl3 dissolved in 120 ml of solution?

Answer 1

The molarity of the solution is 1.3875M

Step-by-step explanation

The mass of FeCl3 is 27 grams

The volume of the solution is 120mL

Follow the steps below to find the molarity of the solution.

Step 1; Write the formula for calculating the molarity

`\text{ Molarity = }\frac{\text{ moles of solute}}{\text{ volume of solution in liters}}`

Step 2; Find the number of moles of the solute

`\text{ mole }=\frac{\text{ mass}}{\text{ molar mass}}`

Recall, that the molar mass of FeCl3 is 162.2 g/mol

`\begin{gathered} \text{ mole = }\frac{\text{ 27}}{\text{ 162.2}} \\ \text{ mole = 0.1665 mole} \end{gathered}`

Step 3 ; convert the mL to Liters

Recall, that 1mL is equivalent to 0.001L

`\begin{gathered} \text{ 1mL }\rightarrow\text{ 0.001L} \\ \text{ 120mL }\rightarrow\text{ xL} \\ \text{ cross multiply} \\ \text{ 1mL }*\text{ xL = 120mL }*\text{ 0.001} \\ x\text{ = }\frac{120\text{ x 0.001}}{1} \\ \text{ x = 0.120L} \end{gathered}`

Therefore, the volume of the solution in liters is 0.120L

Step 4; Find the molarity by using the formula in step 1

`\begin{gathered} \text{ Molarity = }\frac{\text{ 0.1665}}{0.120} \\ \text{ Molarity = 1.3875 M} \end{gathered}`

Therefore, the molarity of the solution is 1.3875M