Question

How would you prepare exactly 3.0 litre of 1.0 M NaOH by mixing proportions of stock solutions of 2.50 M NaOH and 0.40 M NaOH. No water is to be used.

Answer 1

Let V mL of 2.50 M NaOH be mixed with (3000 - V) mL of 0.40 MNaOH

Meq. of 2.50 MNaOH + Meq. of 0.4 M NaOH = Meq. of 1.0 M NaOH 

2.50 x V+ 0.4 (3000- V) = 3 x 1000 x 1 (M = N) 

V= 857.14 mL

857.14 mL of 2.50 M NaOH and 2142.96 mL of 0.4 M NaOH are to be mixed.