Question

A technician needs 500.0mL of a 0.500 M MgCl2 solution for some lab procedures. The stock bottle is labeled 4.00 M MgCl2. What volume in Ml of stock solution should the technician use?

Answer 1

Step-by-step explanation:

To solve this problem, we need to obtain the number of moles of the solute we desired to prepare;

Number of moles = molarity x volume

Parameters given;

volume of solution = 500mL = 0.5L

molarity of solution = 0.5M

Number of moles = 0.5 x 0.5 = 0.25moles

Now to know the volume stock to take;

Volume of stock =
`(number of moles )/(molarity)`

molarity of stock = 4M

volume =
`(0.25)/(4)` = 0.0625L or 62.5mL