Question

Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00×10−2 M . The diluted solution is then placed in a spray bottle for application on the desired surfaces.How many moles of luminol are present in 2.00 L of the diluted spray?

Answer 1

Answer:

0.12 moles of luminol.

Explanation:

To solve this problem, we have to understand the concept of molarity: The molarity (M) of a solution is the number of moles of solute dissolved in one liter of solution. To calculate the molarity of a solution, divide the moles of solute by the volume of the solution expressed in liters:

$Molarity\text{ }(M)=\frac{moles\text{ of solute}}{liters\text{ of solution}}=\frac{mol}{L}.$

As we have the molarity of luminol (6.00 x 10⁻² M), and liters of the solution (2.00 L), we just have to solve for 'moles of solute' and replace the given data, like this:

$\begin{gathered} moles\text{ of solute=Molarity}\cdot liters\text{ of solution,} \\ moles\text{ of solute=6.00}\cdot10^{-2}M\cdot2.00L, \\ moles\text{ of solute=0.12 moles.} \end{gathered}$

The answer would be that we have 0.12 moles of luminol in a 2.00 L solution with a 6.00 x 10⁻² M concentration.