Question

If 70.0 mL of water is added to 30.0 mL of 0.400 M solution of NaOH, what is the new concentration of NaOH?

Answer 1

. 4 mol/liter = .0004 mol/mL
30 * .0004 = 0.012 mol NaOH

.012 mol NaOH in 100 mL is .12 mol/liter