Calculate [OH-] for a strong base solution: 12.0 mL of 1.50×10^−2 M Ca(OH)2 diluted to 440.0 mL.

Question

How do i do this?

Answer 1

Use   Amount = volume x concentration

To start with, you had (12.0 x 10^-3 L x 1.50 x 10^-2 mol/L  x 2) mol OH-. (why did I multiply by 2?).

This amount does not change when you dilute, so divide it by your final volume, which is 0.4400 L, to get concentration.

If your instructor is fussy about significant figures, think how many you should use.

Hint for dilution problems: M1V12 = M2V2