Question

Please send me the correct solutions.

Your lab needs a 8 liter stock solution of sodium chloride concentrated enough to make 79 L of 189.9 mM sodium chloride (FW = 58.45). The concentration of the stock solution you need to make is ____ M. You will need to measure out ____ grams of NaCl in order to make this stock solution.

Answer 1

Answer – We are given, M1 = ? , M2 = 189.9 mM = 0.1899 M

V1 = 8 L , V2 = 79 L

We know dilution law

M1V1 = M2V2

So, M1 = M2V2/V1

            = 0.1899 M * 79 L / 8.0 L

            = 1.87 M

The concentration of the stock solution you need to make is 1.87 M.

Now we have volume and molarity need to calculate the moles of NaCl

Moles of NaCl = 1.87 M * 8.0 L

                         = 15.00 moles

Mass of NaCl = 15.00 g * 58.44 g/mol

                        = 877 g

You will need to measure out 877 grams of NaCl in order to make this stock solution.