Stock solution of 1 M NaOH and 05 M NaCl are provided to you

Stock solution of 1 M NaOH and 0.5 M NaCl are provided to you. You need to make a 100mL of a single solution containing 10mM NaOH and 1mM NaCl. How do you do this?

Solution

Consider the formula, C1V1 = C2V2.

Where, C1 = Concentration of the stock = 1 M NaoH

V1 = Volume of stock to be taken = ?

C2 = Concentration of final volume = 10 mM of NaoH or 0.01 M of NaOH

V2 = Volume of final solution =100 mL

Now, substitute the values in the given formula.

1 M* V1 = 0.01 M*100 mL

V1 = 1 mL

Take 1 mL from the stock and make the volume up to 100 mL, which gives the concentration of 10 mM NaOH.

Similarly, to prepare the NaCl solution,

C1 = Concentration of the stock = 0.5 M NaCl

V1 = Volume of stock to be taken = ?

C2 = Concentration of final volume = 1 mM of NaCl or 0.001 M of NaCl

V2 = Volume of final solution =100 mL

Now, substitute the values in the given formula.

0.5 M* V1 = 0.001 M*100 mL

V1 = 0.2 mL

Take 0.2 mL from the stock solution and make the volume up to 100 mL, which gives the concentration of 1 mM NaCl.